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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/dom/ImageBitmap.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/dom/DOMPrefs.h"
#include "mozilla/dom/HTMLMediaElementBinding.h"
#include "mozilla/dom/ImageBitmapBinding.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/StructuredCloneTags.h"
#include "mozilla/dom/WorkerPrivate.h"
#include "mozilla/dom/WorkerRunnable.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Swizzle.h"
#include "mozilla/Mutex.h"
#include "ImageBitmapColorUtils.h"
#include "ImageBitmapUtils.h"
#include "ImageUtils.h"
#include "imgTools.h"

using namespace mozilla::gfx;
using namespace mozilla::layers;
using mozilla::dom::HTMLMediaElementBinding::HAVE_METADATA;
using mozilla::dom::HTMLMediaElementBinding::NETWORK_EMPTY;

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(ImageBitmap, mParent)
NS_IMPL_CYCLE_COLLECTING_ADDREF(ImageBitmap)
NS_IMPL_CYCLE_COLLECTING_RELEASE(ImageBitmap)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageBitmap)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

/* This class observes shutdown notifications and sends that notification
 * to the worker thread if the image bitmap is on a worker thread.
 */
class ImageBitmapShutdownObserver final : public nsIObserver {
 public:
  explicit ImageBitmapShutdownObserver(ImageBitmap* aImageBitmap)
      : mImageBitmap(nullptr) {
    if (NS_IsMainThread()) {
      mImageBitmap = aImageBitmap;
    } else {
      WorkerPrivate* workerPrivate = GetCurrentThreadWorkerPrivate();
      MOZ_ASSERT(workerPrivate);
      mMainThreadEventTarget = workerPrivate->MainThreadEventTarget();
      mSendToWorkerTask = new SendShutdownToWorkerThread(aImageBitmap);
    }
  }

  void RegisterObserver() {
    if (NS_IsMainThread()) {
      nsContentUtils::RegisterShutdownObserver(this);
      return;
    }

    MOZ_ASSERT(mMainThreadEventTarget);
    RefPtr<ImageBitmapShutdownObserver> self = this;
    nsCOMPtr<nsIRunnable> r =
        NS_NewRunnableFunction("ImageBitmapShutdownObserver::RegisterObserver",
                               [self]() { self->RegisterObserver(); });

    mMainThreadEventTarget->Dispatch(r.forget());
  }

  void UnregisterObserver() {
    if (NS_IsMainThread()) {
      nsContentUtils::UnregisterShutdownObserver(this);
      return;
    }

    MOZ_ASSERT(mMainThreadEventTarget);
    RefPtr<ImageBitmapShutdownObserver> self = this;
    nsCOMPtr<nsIRunnable> r =
        NS_NewRunnableFunction("ImageBitmapShutdownObserver::RegisterObserver",
                               [self]() { self->UnregisterObserver(); });

    mMainThreadEventTarget->Dispatch(r.forget());
  }

  void Clear() {
    mImageBitmap = nullptr;
    if (mSendToWorkerTask) {
      mSendToWorkerTask->mImageBitmap = nullptr;
    }
  }

  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIOBSERVER
 private:
  ~ImageBitmapShutdownObserver() {}

  class SendShutdownToWorkerThread : public MainThreadWorkerControlRunnable {
   public:
    explicit SendShutdownToWorkerThread(ImageBitmap* aImageBitmap)
        : MainThreadWorkerControlRunnable(GetCurrentThreadWorkerPrivate()),
          mImageBitmap(aImageBitmap) {}

    bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
      if (mImageBitmap) {
        mImageBitmap->OnShutdown();
        mImageBitmap = nullptr;
      }
      return true;
    }

    ImageBitmap* mImageBitmap;
  };

  ImageBitmap* mImageBitmap;
  nsCOMPtr<nsIEventTarget> mMainThreadEventTarget;
  RefPtr<SendShutdownToWorkerThread> mSendToWorkerTask;
};

NS_IMPL_ISUPPORTS(ImageBitmapShutdownObserver, nsIObserver)

NS_IMETHODIMP
ImageBitmapShutdownObserver::Observe(nsISupports* aSubject, const char* aTopic,
                                     const char16_t* aData) {
  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
    if (mSendToWorkerTask) {
      mSendToWorkerTask->Dispatch();
    } else {
      if (mImageBitmap) {
        mImageBitmap->OnShutdown();
        mImageBitmap = nullptr;
      }
    }
    nsContentUtils::UnregisterShutdownObserver(this);
  }

  return NS_OK;
}

/*
 * If either aRect.width or aRect.height are negative, then return a new IntRect
 * which represents the same rectangle as the aRect does but with positive width
 * and height.
 */
static IntRect FixUpNegativeDimension(const IntRect& aRect, ErrorResult& aRv) {
  gfx::IntRect rect = aRect;

  // fix up negative dimensions
  if (rect.width < 0) {
    CheckedInt32 checkedX = CheckedInt32(rect.x) + rect.width;

    if (!checkedX.isValid()) {
      aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
      return rect;
    }

    rect.x = checkedX.value();
    rect.width = -(rect.width);
  }

  if (rect.height < 0) {
    CheckedInt32 checkedY = CheckedInt32(rect.y) + rect.height;

    if (!checkedY.isValid()) {
      aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
      return rect;
    }

    rect.y = checkedY.value();
    rect.height = -(rect.height);
  }

  return rect;
}

/*
 * This helper function copies the data of the given DataSourceSurface,
 *  _aSurface_, in the given area, _aCropRect_, into a new DataSourceSurface.
 * This might return null if it can not create a new SourceSurface or it cannot
 * read data from the given _aSurface_.
 *
 * Warning: Even though the area of _aCropRect_ is just the same as the size of
 *          _aSurface_, this function still copy data into a new
 *          DataSourceSurface.
 */
static already_AddRefed<DataSourceSurface> CropAndCopyDataSourceSurface(
    DataSourceSurface* aSurface, const IntRect& aCropRect) {
  MOZ_ASSERT(aSurface);

  // Check the aCropRect
  ErrorResult error;
  const IntRect positiveCropRect = FixUpNegativeDimension(aCropRect, error);
  if (NS_WARN_IF(error.Failed())) {
    error.SuppressException();
    return nullptr;
  }

  // Calculate the size of the new SourceSurface.
  // We cannot keep using aSurface->GetFormat() to create new DataSourceSurface,
  // since it might be SurfaceFormat::B8G8R8X8 which does not handle opacity,
  // however the specification explicitly define that "If any of the pixels on
  // this rectangle are outside the area where the input bitmap was placed, then
  // they will be transparent black in output."
  // So, instead, we force the output format to be SurfaceFormat::B8G8R8A8.
  const SurfaceFormat format = SurfaceFormat::B8G8R8A8;
  const int bytesPerPixel = BytesPerPixel(format);
  const IntSize dstSize =
      IntSize(positiveCropRect.width, positiveCropRect.height);
  const uint32_t dstStride = dstSize.width * bytesPerPixel;

  // Create a new SourceSurface.
  RefPtr<DataSourceSurface> dstDataSurface =
      Factory::CreateDataSourceSurfaceWithStride(dstSize, format, dstStride,
                                                 true);

  if (NS_WARN_IF(!dstDataSurface)) {
    return nullptr;
  }

  // Only do copying and cropping when the positiveCropRect intersects with
  // the size of aSurface.
  const IntRect surfRect(IntPoint(0, 0), aSurface->GetSize());
  if (surfRect.Intersects(positiveCropRect)) {
    const IntRect surfPortion = surfRect.Intersect(positiveCropRect);
    const IntPoint dest(std::max(0, surfPortion.X() - positiveCropRect.X()),
                        std::max(0, surfPortion.Y() - positiveCropRect.Y()));

    // Copy the raw data into the newly created DataSourceSurface.
    DataSourceSurface::ScopedMap srcMap(aSurface, DataSourceSurface::READ);
    DataSourceSurface::ScopedMap dstMap(dstDataSurface,
                                        DataSourceSurface::WRITE);
    if (NS_WARN_IF(!srcMap.IsMapped()) || NS_WARN_IF(!dstMap.IsMapped())) {
      return nullptr;
    }

    uint8_t* srcBufferPtr = srcMap.GetData() +
                            surfPortion.y * srcMap.GetStride() +
                            surfPortion.x * bytesPerPixel;
    uint8_t* dstBufferPtr =
        dstMap.GetData() + dest.y * dstMap.GetStride() + dest.x * bytesPerPixel;
    CheckedInt<uint32_t> copiedBytesPerRaw =
        CheckedInt<uint32_t>(surfPortion.width) * bytesPerPixel;
    if (!copiedBytesPerRaw.isValid()) {
      return nullptr;
    }

    for (int i = 0; i < surfPortion.height; ++i) {
      memcpy(dstBufferPtr, srcBufferPtr, copiedBytesPerRaw.value());
      srcBufferPtr += srcMap.GetStride();
      dstBufferPtr += dstMap.GetStride();
    }
  }

  return dstDataSurface.forget();
}

/*
 * Encapsulate the given _aSurface_ into a layers::SourceSurfaceImage.
 */
static already_AddRefed<layers::Image> CreateImageFromSurface(
    SourceSurface* aSurface) {
  MOZ_ASSERT(aSurface);
  RefPtr<layers::SourceSurfaceImage> image =
      new layers::SourceSurfaceImage(aSurface->GetSize(), aSurface);
  return image.forget();
}

/*
 * CreateImageFromRawData(), CreateSurfaceFromRawData() and
 * CreateImageFromRawDataInMainThreadSyncTask are helpers for
 * create-from-ImageData case
 */
static already_AddRefed<SourceSurface> CreateSurfaceFromRawData(
    const gfx::IntSize& aSize, uint32_t aStride, gfx::SurfaceFormat aFormat,
    uint8_t* aBuffer, uint32_t aBufferLength, const Maybe<IntRect>& aCropRect) {
  MOZ_ASSERT(!aSize.IsEmpty());
  MOZ_ASSERT(aBuffer);

  // Wrap the source buffer into a SourceSurface.
  RefPtr<DataSourceSurface> dataSurface =
      Factory::CreateWrappingDataSourceSurface(aBuffer, aStride, aSize,
                                               aFormat);

  if (NS_WARN_IF(!dataSurface)) {
    return nullptr;
  }

  // The temporary cropRect variable is equal to the size of source buffer if we
  // do not need to crop, or it equals to the given cropping size.
  const IntRect cropRect =
      aCropRect.valueOr(IntRect(0, 0, aSize.width, aSize.height));

  // Copy the source buffer in the _cropRect_ area into a new SourceSurface.
  RefPtr<DataSourceSurface> result =
      CropAndCopyDataSourceSurface(dataSurface, cropRect);

  if (NS_WARN_IF(!result)) {
    return nullptr;
  }

  return result.forget();
}

static already_AddRefed<layers::Image> CreateImageFromRawData(
    const gfx::IntSize& aSize, uint32_t aStride, gfx::SurfaceFormat aFormat,
    uint8_t* aBuffer, uint32_t aBufferLength, const Maybe<IntRect>& aCropRect) {
  MOZ_ASSERT(NS_IsMainThread());

  // Copy and crop the source buffer into a SourceSurface.
  RefPtr<SourceSurface> rgbaSurface = CreateSurfaceFromRawData(
      aSize, aStride, aFormat, aBuffer, aBufferLength, aCropRect);

  if (NS_WARN_IF(!rgbaSurface)) {
    return nullptr;
  }

  // Convert RGBA to BGRA
  RefPtr<DataSourceSurface> rgbaDataSurface = rgbaSurface->GetDataSurface();
  DataSourceSurface::ScopedMap rgbaMap(rgbaDataSurface,
                                       DataSourceSurface::READ);
  if (NS_WARN_IF(!rgbaMap.IsMapped())) {
    return nullptr;
  }

  RefPtr<DataSourceSurface> bgraDataSurface =
      Factory::CreateDataSourceSurfaceWithStride(rgbaDataSurface->GetSize(),
                                                 SurfaceFormat::B8G8R8A8,
                                                 rgbaMap.GetStride());
  if (NS_WARN_IF(!bgraDataSurface)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap bgraMap(bgraDataSurface,
                                       DataSourceSurface::WRITE);
  if (NS_WARN_IF(!bgraMap.IsMapped())) {
    return nullptr;
  }

  SwizzleData(rgbaMap.GetData(), rgbaMap.GetStride(), SurfaceFormat::R8G8B8A8,
              bgraMap.GetData(), bgraMap.GetStride(), SurfaceFormat::B8G8R8A8,
              bgraDataSurface->GetSize());

  // Create an Image from the BGRA SourceSurface.
  RefPtr<layers::Image> image = CreateImageFromSurface(bgraDataSurface);

  if (NS_WARN_IF(!image)) {
    return nullptr;
  }

  return image.forget();
}

/*
 * This is a synchronous task.
 * This class is used to create a layers::SourceSurfaceImage from raw data in
 * the main thread. While creating an ImageBitmap from an ImageData, we need to
 * create a SouceSurface from the ImageData's raw data and then set the
 * SourceSurface into a layers::SourceSurfaceImage. However, the
 * layers::SourceSurfaceImage asserts the setting operation in the main thread,
 * so if we are going to create an ImageBitmap from an ImageData off the main
 * thread, we post an event to the main thread to create a
 * layers::SourceSurfaceImage from an ImageData's raw data.
 */
class CreateImageFromRawDataInMainThreadSyncTask final
    : public WorkerMainThreadRunnable {
 public:
  CreateImageFromRawDataInMainThreadSyncTask(
      uint8_t* aBuffer, uint32_t aBufferLength, uint32_t aStride,
      gfx::SurfaceFormat aFormat, const gfx::IntSize& aSize,
      const Maybe<IntRect>& aCropRect, layers::Image** aImage)
      : WorkerMainThreadRunnable(
            GetCurrentThreadWorkerPrivate(),
            NS_LITERAL_CSTRING("ImageBitmap :: Create Image from Raw Data")),
        mImage(aImage),
        mBuffer(aBuffer),
        mBufferLength(aBufferLength),
        mStride(aStride),
        mFormat(aFormat),
        mSize(aSize),
        mCropRect(aCropRect) {
    MOZ_ASSERT(!(*aImage),
               "Don't pass an existing Image into "
               "CreateImageFromRawDataInMainThreadSyncTask.");
  }

  bool MainThreadRun() override {
    RefPtr<layers::Image> image = CreateImageFromRawData(
        mSize, mStride, mFormat, mBuffer, mBufferLength, mCropRect);

    if (NS_WARN_IF(!image)) {
      return false;
    }

    image.forget(mImage);

    return true;
  }

 private:
  layers::Image** mImage;
  uint8_t* mBuffer;
  uint32_t mBufferLength;
  uint32_t mStride;
  gfx::SurfaceFormat mFormat;
  gfx::IntSize mSize;
  const Maybe<IntRect>& mCropRect;
};

/*
 * A wrapper to the nsLayoutUtils::SurfaceFromElement() function followed by the
 * security checking.
 */
template <class ElementType>
static already_AddRefed<SourceSurface> GetSurfaceFromElement(
    nsIGlobalObject* aGlobal, ElementType& aElement, bool* aWriteOnly,
    ErrorResult& aRv) {
  nsLayoutUtils::SurfaceFromElementResult res =
      nsLayoutUtils::SurfaceFromElement(
          &aElement, nsLayoutUtils::SFE_WANT_FIRST_FRAME_IF_IMAGE);

  RefPtr<SourceSurface> surface = res.GetSourceSurface();

  if (NS_WARN_IF(!surface)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  *aWriteOnly = res.mIsWriteOnly;

  return surface.forget();
}

/*
 * The specification doesn't allow to create an ImegeBitmap from a vector image.
 * This function is used to check if the given HTMLImageElement contains a
 * raster image.
 */
static bool HasRasterImage(HTMLImageElement& aImageEl) {
  nsresult rv;

  nsCOMPtr<imgIRequest> imgRequest;
  rv = aImageEl.GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
                           getter_AddRefs(imgRequest));
  if (NS_SUCCEEDED(rv) && imgRequest) {
    nsCOMPtr<imgIContainer> imgContainer;
    rv = imgRequest->GetImage(getter_AddRefs(imgContainer));
    if (NS_SUCCEEDED(rv) && imgContainer &&
        imgContainer->GetType() == imgIContainer::TYPE_RASTER) {
      return true;
    }
  }

  return false;
}

ImageBitmap::ImageBitmap(nsIGlobalObject* aGlobal, layers::Image* aData,
                         bool aWriteOnly, gfxAlphaType aAlphaType)
    : mParent(aGlobal),
      mData(aData),
      mSurface(nullptr),
      mDataWrapper(new ImageUtils(mData)),
      mPictureRect(0, 0, aData->GetSize().width, aData->GetSize().height),
      mAlphaType(aAlphaType),
      mIsCroppingAreaOutSideOfSourceImage(false),
      mAllocatedImageData(false),
      mWriteOnly(aWriteOnly) {
  MOZ_ASSERT(aData, "aData is null in ImageBitmap constructor.");

  mShutdownObserver = new ImageBitmapShutdownObserver(this);
  mShutdownObserver->RegisterObserver();
}

ImageBitmap::~ImageBitmap() {
  if (mShutdownObserver) {
    mShutdownObserver->Clear();
    mShutdownObserver->UnregisterObserver();
    mShutdownObserver = nullptr;
  }
}

JSObject* ImageBitmap::WrapObject(JSContext* aCx,
                                  JS::Handle<JSObject*> aGivenProto) {
  return ImageBitmapBinding::Wrap(aCx, this, aGivenProto);
}

void ImageBitmap::Close() {
  mData = nullptr;
  mSurface = nullptr;
  mDataWrapper = nullptr;
  mPictureRect.SetEmpty();
}

void ImageBitmap::OnShutdown() {
  mShutdownObserver = nullptr;

  Close();
}

void ImageBitmap::SetPictureRect(const IntRect& aRect, ErrorResult& aRv) {
  mPictureRect = FixUpNegativeDimension(aRect, aRv);
}

void ImageBitmap::SetIsCroppingAreaOutSideOfSourceImage(
    const IntSize& aSourceSize, const Maybe<IntRect>& aCroppingRect) {
  // No cropping at all.
  if (aCroppingRect.isNothing()) {
    mIsCroppingAreaOutSideOfSourceImage = false;
    return;
  }

  if (aCroppingRect->X() < 0 || aCroppingRect->Y() < 0 ||
      aCroppingRect->Width() > aSourceSize.width ||
      aCroppingRect->Height() > aSourceSize.height) {
    mIsCroppingAreaOutSideOfSourceImage = true;
  }
}

static already_AddRefed<SourceSurface> ConvertColorFormatIfNeeded(
    RefPtr<SourceSurface> aSurface) {
  const SurfaceFormat srcFormat = aSurface->GetFormat();
  if (srcFormat == SurfaceFormat::R8G8B8A8 ||
      srcFormat == SurfaceFormat::B8G8R8A8 ||
      srcFormat == SurfaceFormat::R8G8B8X8 ||
      srcFormat == SurfaceFormat::B8G8R8X8 ||
      srcFormat == SurfaceFormat::A8R8G8B8 ||
      srcFormat == SurfaceFormat::X8R8G8B8) {
    return aSurface.forget();
  }

  if (srcFormat == SurfaceFormat::A8 || srcFormat == SurfaceFormat::Depth) {
    return nullptr;
  }

  const int bytesPerPixel = BytesPerPixel(SurfaceFormat::B8G8R8A8);
  const IntSize dstSize = aSurface->GetSize();
  const uint32_t dstStride = dstSize.width * bytesPerPixel;

  RefPtr<DataSourceSurface> dstDataSurface =
      Factory::CreateDataSourceSurfaceWithStride(
          dstSize, SurfaceFormat::B8G8R8A8, dstStride);
  if (NS_WARN_IF(!dstDataSurface)) {
    return nullptr;
  }

  RefPtr<DataSourceSurface> srcDataSurface = aSurface->GetDataSurface();
  if (NS_WARN_IF(!srcDataSurface)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap srcMap(srcDataSurface, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap dstMap(dstDataSurface, DataSourceSurface::WRITE);
  if (NS_WARN_IF(!srcMap.IsMapped()) || NS_WARN_IF(!dstMap.IsMapped())) {
    return nullptr;
  }

  int rv = 0;
  if (srcFormat == SurfaceFormat::R8G8B8) {
    rv = RGB24ToBGRA32(srcMap.GetData(), srcMap.GetStride(), dstMap.GetData(),
                       dstMap.GetStride(), dstSize.width, dstSize.height);
  } else if (srcFormat == SurfaceFormat::B8G8R8) {
    rv = BGR24ToBGRA32(srcMap.GetData(), srcMap.GetStride(), dstMap.GetData(),
                       dstMap.GetStride(), dstSize.width, dstSize.height);
  } else if (srcFormat == SurfaceFormat::HSV) {
    rv = HSVToBGRA32((const float*)srcMap.GetData(), srcMap.GetStride(),
                     dstMap.GetData(), dstMap.GetStride(), dstSize.width,
                     dstSize.height);
  } else if (srcFormat == SurfaceFormat::Lab) {
    rv = LabToBGRA32((const float*)srcMap.GetData(), srcMap.GetStride(),
                     dstMap.GetData(), dstMap.GetStride(), dstSize.width,
                     dstSize.height);
  }

  if (NS_WARN_IF(rv != 0)) {
    return nullptr;
  }

  return dstDataSurface.forget();
}

/*
 * The functionality of PrepareForDrawTarget method:
 * (1) Get a SourceSurface from the mData (which is a layers::Image).
 * (2) Convert the SourceSurface to format B8G8R8A8 if the original format is
 *     R8G8B8, B8G8R8, HSV or Lab.
 *     Note: if the original format is A8 or Depth, then return null directly.
 * (3) Do cropping if the size of SourceSurface does not equal to the
 *     mPictureRect.
 * (4) Pre-multiply alpha if needed.
 */
already_AddRefed<SourceSurface> ImageBitmap::PrepareForDrawTarget(
    gfx::DrawTarget* aTarget) {
  MOZ_ASSERT(aTarget);

  if (!mData) {
    return nullptr;
  }

  if (!mSurface) {
    mSurface = mData->GetAsSourceSurface();

    if (!mSurface) {
      return nullptr;
    }
  }

  // Check if we need to convert the format.
  // Convert R8G8B8/B8G8R8/HSV/Lab to B8G8R8A8.
  // Return null if the original format is A8 or Depth.
  mSurface = ConvertColorFormatIfNeeded(mSurface);
  if (NS_WARN_IF(!mSurface)) {
    return nullptr;
  }

  RefPtr<DrawTarget> target = aTarget;
  IntRect surfRect(0, 0, mSurface->GetSize().width, mSurface->GetSize().height);

  // Check if we still need to crop our surface
  if (!mPictureRect.IsEqualEdges(surfRect)) {
    IntRect surfPortion = surfRect.Intersect(mPictureRect);

    // the crop lies entirely outside the surface area, nothing to draw
    if (surfPortion.IsEmpty()) {
      mSurface = nullptr;
      RefPtr<gfx::SourceSurface> surface(mSurface);
      return surface.forget();
    }

    IntPoint dest(std::max(0, surfPortion.X() - mPictureRect.X()),
                  std::max(0, surfPortion.Y() - mPictureRect.Y()));

    // We must initialize this target with mPictureRect.Size() because the
    // specification states that if the cropping area is given, then return an
    // ImageBitmap with the size equals to the cropping area.
    target = target->CreateSimilarDrawTarget(mPictureRect.Size(),
                                             target->GetFormat());

    if (!target) {
      mSurface = nullptr;
      RefPtr<gfx::SourceSurface> surface(mSurface);
      return surface.forget();
    }

    target->CopySurface(mSurface, surfPortion, dest);
    mSurface = target->Snapshot();

    // Make mCropRect match new surface we've cropped to
    mPictureRect.MoveTo(0, 0);
  }

  // Pre-multiply alpha here.
  // Ignore this step if the source surface does not have alpha channel; this
  // kind of source surfaces might come form layers::PlanarYCbCrImage.
  if (mAlphaType == gfxAlphaType::NonPremult &&
      !IsOpaque(mSurface->GetFormat())) {
    MOZ_ASSERT(mSurface->GetFormat() == SurfaceFormat::R8G8B8A8 ||
               mSurface->GetFormat() == SurfaceFormat::B8G8R8A8 ||
               mSurface->GetFormat() == SurfaceFormat::A8R8G8B8);

    RefPtr<DataSourceSurface> dstSurface = mSurface->GetDataSurface();
    MOZ_ASSERT(dstSurface);

    RefPtr<DataSourceSurface> srcSurface;
    DataSourceSurface::MappedSurface srcMap;
    DataSourceSurface::MappedSurface dstMap;

    if (dstSurface->Map(DataSourceSurface::MapType::READ_WRITE, &dstMap)) {
      srcMap = dstMap;
    } else {
      srcSurface = dstSurface;
      if (!srcSurface->Map(DataSourceSurface::READ, &srcMap)) {
        gfxCriticalError()
            << "Failed to map source surface for premultiplying alpha.";
        return nullptr;
      }

      dstSurface = Factory::CreateDataSourceSurface(srcSurface->GetSize(),
                                                    srcSurface->GetFormat());

      if (!dstSurface ||
          !dstSurface->Map(DataSourceSurface::MapType::WRITE, &dstMap)) {
        gfxCriticalError()
            << "Failed to map destination surface for premultiplying alpha.";
        srcSurface->Unmap();
        return nullptr;
      }
    }

    PremultiplyData(srcMap.mData, srcMap.mStride, mSurface->GetFormat(),
                    dstMap.mData, dstMap.mStride, mSurface->GetFormat(),
                    dstSurface->GetSize());

    dstSurface->Unmap();
    if (srcSurface) {
      srcSurface->Unmap();
    }

    mSurface = dstSurface;
  }

  // Replace our surface with one optimized for the target we're about to draw
  // to, under the assumption it'll likely be drawn again to that target.
  // This call should be a no-op for already-optimized surfaces
  mSurface = target->OptimizeSourceSurface(mSurface);

  RefPtr<gfx::SourceSurface> surface(mSurface);
  return surface.forget();
}

already_AddRefed<layers::Image> ImageBitmap::TransferAsImage() {
  RefPtr<layers::Image> image = mData;
  Close();
  return image.forget();
}

UniquePtr<ImageBitmapCloneData> ImageBitmap::ToCloneData() const {
  UniquePtr<ImageBitmapCloneData> result(new ImageBitmapCloneData());
  result->mPictureRect = mPictureRect;
  result->mAlphaType = mAlphaType;
  result->mIsCroppingAreaOutSideOfSourceImage =
      mIsCroppingAreaOutSideOfSourceImage;
  RefPtr<SourceSurface> surface = mData->GetAsSourceSurface();
  result->mSurface = surface->GetDataSurface();
  MOZ_ASSERT(result->mSurface);
  result->mWriteOnly = mWriteOnly;

  return Move(result);
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateFromCloneData(
    nsIGlobalObject* aGlobal, ImageBitmapCloneData* aData) {
  RefPtr<layers::Image> data = CreateImageFromSurface(aData->mSurface);

  RefPtr<ImageBitmap> ret =
    new ImageBitmap(aGlobal, data, aData->mWriteOnly, aData->mAlphaType);

  ret->mAllocatedImageData = true;

  ret->mIsCroppingAreaOutSideOfSourceImage =
      aData->mIsCroppingAreaOutSideOfSourceImage;

  ErrorResult rv;
  ret->SetPictureRect(aData->mPictureRect, rv);
  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap>
ImageBitmap::CreateFromOffscreenCanvas(nsIGlobalObject* aGlobal,
                                       OffscreenCanvas& aOffscreenCanvas,
                                       ErrorResult& aRv) {
  // Check write-only mode.
  bool writeOnly = aOffscreenCanvas.IsWriteOnly();

  nsLayoutUtils::SurfaceFromElementResult res =
      nsLayoutUtils::SurfaceFromOffscreenCanvas(
          &aOffscreenCanvas, nsLayoutUtils::SFE_WANT_FIRST_FRAME_IF_IMAGE);

  RefPtr<SourceSurface> surface = res.GetSourceSurface();

  if (NS_WARN_IF(!surface)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<layers::Image> data = CreateImageFromSurface(surface);

  RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, writeOnly);

  ret->mAllocatedImageData = true;

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, HTMLImageElement& aImageEl,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  // Check if the image element is completely available or not.
  if (!aImageEl.Complete()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  // Check if the image element is a bitmap (e.g. it's a vector graphic) or not.
  if (!HasRasterImage(aImageEl)) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  bool writeOnly = true;

  // Get the SourceSurface out from the image element and then do security
  // checking.
  RefPtr<SourceSurface> surface = GetSurfaceFromElement(aGlobal, aImageEl,
                                                        &writeOnly, aRv);

  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  // Create ImageBitmap.
  RefPtr<layers::Image> data = CreateImageFromSurface(surface);

  if (NS_WARN_IF(!data)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, writeOnly);

  // Set the picture rectangle.
  if (ret && aCropRect.isSome()) {
    ret->SetPictureRect(aCropRect.ref(), aRv);
  }

  // Set mIsCroppingAreaOutSideOfSourceImage.
  ret->SetIsCroppingAreaOutSideOfSourceImage(surface->GetSize(), aCropRect);

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, HTMLVideoElement& aVideoEl,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  aVideoEl.MarkAsContentSource(
      mozilla::dom::HTMLVideoElement::CallerAPI::CREATE_IMAGEBITMAP);

  // Check network state.
  if (aVideoEl.NetworkState() == NETWORK_EMPTY) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  // Check ready state.
  // Cannot be HTMLMediaElement::HAVE_NOTHING or
  // HTMLMediaElement::HAVE_METADATA.
  if (aVideoEl.ReadyState() <= HAVE_METADATA) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  // Check security.
  nsCOMPtr<nsIPrincipal> principal = aVideoEl.GetCurrentVideoPrincipal();
  bool CORSUsed = aVideoEl.GetCORSMode() != CORS_NONE;
  bool writeOnly = CheckWriteOnlySecurity(CORSUsed, principal);

  // Create ImageBitmap.
  RefPtr<layers::Image> data = aVideoEl.GetCurrentImage();
  if (!data) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }
  RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, writeOnly);

  // Set the picture rectangle.
  if (ret && aCropRect.isSome()) {
    ret->SetPictureRect(aCropRect.ref(), aRv);
  }

  // Set mIsCroppingAreaOutSideOfSourceImage.
  ret->SetIsCroppingAreaOutSideOfSourceImage(data->GetSize(), aCropRect);

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvasEl,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  if (aCanvasEl.Width() == 0 || aCanvasEl.Height() == 0) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  bool writeOnly = true;
  RefPtr<SourceSurface> surface = GetSurfaceFromElement(aGlobal, aCanvasEl,
                                                        &writeOnly, aRv);

  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  if (!writeOnly) {
    writeOnly = aCanvasEl.IsWriteOnly();
  }

  // Crop the source surface if needed.
  RefPtr<SourceSurface> croppedSurface;
  IntRect cropRect = aCropRect.valueOr(IntRect());

  // If the HTMLCanvasElement's rendering context is WebGL, then the snapshot
  // we got from the HTMLCanvasElement is a DataSourceSurface which is a copy
  // of the rendering context. We handle cropping in this case.
  bool needToReportMemoryAllocation = false;
  if ((aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL1 ||
       aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL2) &&
      aCropRect.isSome()) {
    RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
    croppedSurface = CropAndCopyDataSourceSurface(dataSurface, cropRect);
    cropRect.MoveTo(0, 0);
    needToReportMemoryAllocation = true;
  } else {
    croppedSurface = surface;
  }

  if (NS_WARN_IF(!croppedSurface)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  // Create an Image from the SourceSurface.
  RefPtr<layers::Image> data = CreateImageFromSurface(croppedSurface);

  if (NS_WARN_IF(!data)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, writeOnly);

  if (needToReportMemoryAllocation) {
    ret->mAllocatedImageData = true;
  }

  // Set the picture rectangle.
  if (ret && aCropRect.isSome()) {
    ret->SetPictureRect(cropRect, aRv);
  }

  // Set mIsCroppingAreaOutSideOfSourceImage.
  ret->SetIsCroppingAreaOutSideOfSourceImage(surface->GetSize(), aCropRect);

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, ImageData& aImageData,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  // Copy data into SourceSurface.
  dom::Uint8ClampedArray array;
  DebugOnly<bool> inited = array.Init(aImageData.GetDataObject());
  MOZ_ASSERT(inited);

  array.ComputeLengthAndData();
  const SurfaceFormat FORMAT = SurfaceFormat::R8G8B8A8;
  // ImageData's underlying data is not alpha-premultiplied.
  const auto alphaType = gfxAlphaType::NonPremult;
  const uint32_t BYTES_PER_PIXEL = BytesPerPixel(FORMAT);
  const uint32_t imageWidth = aImageData.Width();
  const uint32_t imageHeight = aImageData.Height();
  const uint32_t imageStride = imageWidth * BYTES_PER_PIXEL;
  const uint32_t dataLength = array.Length();
  const gfx::IntSize imageSize(imageWidth, imageHeight);

  // Check the ImageData is neutered or not.
  if (imageWidth == 0 || imageHeight == 0 ||
      (imageWidth * imageHeight * BYTES_PER_PIXEL) != dataLength) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  // Create and Crop the raw data into a layers::Image
  RefPtr<layers::Image> data;
  if (NS_IsMainThread()) {
    data = CreateImageFromRawData(imageSize, imageStride, FORMAT, array.Data(),
                                  dataLength, aCropRect);
  } else {
    RefPtr<CreateImageFromRawDataInMainThreadSyncTask> task =
        new CreateImageFromRawDataInMainThreadSyncTask(
            array.Data(), dataLength, imageStride, FORMAT, imageSize, aCropRect,
            getter_AddRefs(data));
    task->Dispatch(Terminating, aRv);
  }

  if (NS_WARN_IF(!data)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  // Create an ImageBimtap.
  RefPtr<ImageBitmap> ret =
    new ImageBitmap(aGlobal, data, false /* write-only */, alphaType);

  ret->mAllocatedImageData = true;

  // The cropping information has been handled in the CreateImageFromRawData()
  // function.

  // Set mIsCroppingAreaOutSideOfSourceImage.
  ret->SetIsCroppingAreaOutSideOfSourceImage(imageSize, aCropRect);

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, CanvasRenderingContext2D& aCanvasCtx,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  // Check write-only mode.
  bool writeOnly =
      aCanvasCtx.GetCanvas()->IsWriteOnly() || aCanvasCtx.IsWriteOnly();

  RefPtr<SourceSurface> surface = aCanvasCtx.GetSurfaceSnapshot();

  if (NS_WARN_IF(!surface)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  const IntSize surfaceSize = surface->GetSize();
  if (surfaceSize.width == 0 || surfaceSize.height == 0) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  RefPtr<layers::Image> data = CreateImageFromSurface(surface);

  if (NS_WARN_IF(!data)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<ImageBitmap> ret =
    new ImageBitmap(aGlobal, data, writeOnly);

  ret->mAllocatedImageData = true;

  // Set the picture rectangle.
  if (ret && aCropRect.isSome()) {
    ret->SetPictureRect(aCropRect.ref(), aRv);
  }

  // Set mIsCroppingAreaOutSideOfSourceImage.
  ret->SetIsCroppingAreaOutSideOfSourceImage(surface->GetSize(), aCropRect);

  return ret.forget();
}

/* static */ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
    nsIGlobalObject* aGlobal, ImageBitmap& aImageBitmap,
    const Maybe<IntRect>& aCropRect, ErrorResult& aRv) {
  if (!aImageBitmap.mData) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<layers::Image> data = aImageBitmap.mData;
  RefPtr<ImageBitmap> ret =
      new ImageBitmap(aGlobal, data, aImageBitmap.mWriteOnly,
                      aImageBitmap.mAlphaType);

  // Set the picture rectangle.
  if (ret && aCropRect.isSome()) {
    ret->SetPictureRect(aCropRect.ref(), aRv);
  }

  // Set mIsCroppingAreaOutSideOfSourceImage.
  if (aImageBitmap.mIsCroppingAreaOutSideOfSourceImage == true) {
    ret->mIsCroppingAreaOutSideOfSourceImage = true;
  } else {
    ret->SetIsCroppingAreaOutSideOfSourceImage(aImageBitmap.mPictureRect.Size(),
                                               aCropRect);
  }

  return ret.forget();
}

class FulfillImageBitmapPromise {
 protected:
  FulfillImageBitmapPromise(Promise* aPromise, ImageBitmap* aImageBitmap)
      : mPromise(aPromise), mImageBitmap(aImageBitmap) {
    MOZ_ASSERT(aPromise);
  }

  void DoFulfillImageBitmapPromise() { mPromise->MaybeResolve(mImageBitmap); }

 private:
  RefPtr<Promise> mPromise;
  RefPtr<ImageBitmap> mImageBitmap;
};

class FulfillImageBitmapPromiseTask final : public Runnable,
                                            public FulfillImageBitmapPromise {
 public:
  FulfillImageBitmapPromiseTask(Promise* aPromise, ImageBitmap* aImageBitmap)
      : Runnable("dom::FulfillImageBitmapPromiseTask"),
        FulfillImageBitmapPromise(aPromise, aImageBitmap) {}

  NS_IMETHOD Run() override {
    DoFulfillImageBitmapPromise();
    return NS_OK;
  }
};

class FulfillImageBitmapPromiseWorkerTask final
    : public WorkerSameThreadRunnable,
      public FulfillImageBitmapPromise {
 public:
  FulfillImageBitmapPromiseWorkerTask(Promise* aPromise,
                                      ImageBitmap* aImageBitmap)
      : WorkerSameThreadRunnable(GetCurrentThreadWorkerPrivate()),
        FulfillImageBitmapPromise(aPromise, aImageBitmap) {}

  bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
    DoFulfillImageBitmapPromise();
    return true;
  }
};

static void AsyncFulfillImageBitmapPromise(Promise* aPromise,
                                           ImageBitmap* aImageBitmap) {
  if (NS_IsMainThread()) {
    nsCOMPtr<nsIRunnable> task =
        new FulfillImageBitmapPromiseTask(aPromise, aImageBitmap);
    NS_DispatchToCurrentThread(task);  // Actually, to the main-thread.
  } else {
    RefPtr<FulfillImageBitmapPromiseWorkerTask> task =
        new FulfillImageBitmapPromiseWorkerTask(aPromise, aImageBitmap);
    task->Dispatch();  // Actually, to the current worker-thread.
  }
}

class CreateImageBitmapFromBlobRunnable;
class CreateImageBitmapFromBlobHolder;

class CreateImageBitmapFromBlob final : public CancelableRunnable,
                                        public imgIContainerCallback {
  friend class CreateImageBitmapFromBlobRunnable;

 public:
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_IMGICONTAINERCALLBACK

  static already_AddRefed<CreateImageBitmapFromBlob> Create(
      Promise* aPromise, nsIGlobalObject* aGlobal, Blob& aBlob,
      const Maybe<IntRect>& aCropRect, nsIEventTarget* aMainThreadEventTarget);

  NS_IMETHOD Run() override {
    MOZ_ASSERT(IsCurrentThread());

    nsresult rv = StartDecodeAndCropBlob();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      DecodeAndCropBlobCompletedMainThread(nullptr, rv);
    }

    return NS_OK;
  }

  // Called by the WorkerHolder.
  void WorkerShuttingDown();

 private:
  CreateImageBitmapFromBlob(Promise* aPromise, nsIGlobalObject* aGlobal,
                            already_AddRefed<nsIInputStream> aInputStream,
                            const nsACString& aMimeType,
                            const Maybe<IntRect>& aCropRect,
                            nsIEventTarget* aMainThreadEventTarget)
      : CancelableRunnable("dom::CreateImageBitmapFromBlob"),
        mMutex("dom::CreateImageBitmapFromBlob::mMutex"),
        mPromise(aPromise),
        mGlobalObject(aGlobal),
        mInputStream(Move(aInputStream)),
        mMimeType(aMimeType),
        mCropRect(aCropRect),
        mOriginalCropRect(aCropRect),
        mMainThreadEventTarget(aMainThreadEventTarget),
        mThread(GetCurrentVirtualThread()) {}

  virtual ~CreateImageBitmapFromBlob() {}

  bool IsCurrentThread() const { return mThread == GetCurrentVirtualThread(); }

  // Called on the owning thread.
  nsresult StartDecodeAndCropBlob();

  // Will be called when the decoding + cropping is completed on the
  // main-thread. This could the not the owning thread!
  void DecodeAndCropBlobCompletedMainThread(layers::Image* aImage,
                                            nsresult aStatus);

  // Will be called when the decoding + cropping is completed on the owning
  // thread.
  void DecodeAndCropBlobCompletedOwningThread(layers::Image* aImage,
                                              nsresult aStatus);

  // This is called on the main-thread only.
  nsresult DecodeAndCropBlob();

  Mutex mMutex;

  // The access to this object is protected by mutex but is always nullified on
  // the owning thread.
  UniquePtr<CreateImageBitmapFromBlobHolder> mWorkerHolder;

  // Touched only on the owning thread.
  RefPtr<Promise> mPromise;

  // Touched only on the owning thread.
  nsCOMPtr<nsIGlobalObject> mGlobalObject;

  nsCOMPtr<nsIInputStream> mInputStream;
  nsCString mMimeType;
  Maybe<IntRect> mCropRect;
  Maybe<IntRect> mOriginalCropRect;
  IntSize mSourceSize;

  nsCOMPtr<nsIEventTarget> mMainThreadEventTarget;
  void* mThread;
};

NS_IMPL_ISUPPORTS_INHERITED(CreateImageBitmapFromBlob, CancelableRunnable,
                            imgIContainerCallback)

class CreateImageBitmapFromBlobRunnable : public WorkerRunnable {
 public:
  explicit CreateImageBitmapFromBlobRunnable(WorkerPrivate* aWorkerPrivate,
                                             CreateImageBitmapFromBlob* aTask,
                                             layers::Image* aImage,
                                             nsresult aStatus)
      : WorkerRunnable(aWorkerPrivate),
        mTask(aTask),
        mImage(aImage),
        mStatus(aStatus) {}

  bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
    mTask->DecodeAndCropBlobCompletedOwningThread(mImage, mStatus);
    return true;
  }

 private:
  RefPtr<CreateImageBitmapFromBlob> mTask;
  RefPtr<layers::Image> mImage;
  nsresult mStatus;
};

// This class keeps the worker alive and it informs CreateImageBitmapFromBlob
// when it goes away.
class CreateImageBitmapFromBlobHolder final : public WorkerHolder {
 public:
  CreateImageBitmapFromBlobHolder(WorkerPrivate* aWorkerPrivate,
                                  CreateImageBitmapFromBlob* aTask)
      : WorkerHolder("CreateImageBitmapFromBlobHolder"),
        mWorkerPrivate(aWorkerPrivate),
        mTask(aTask),
        mNotified(false) {}

  bool Notify(WorkerStatus aStatus) override {
    if (!mNotified) {
      mNotified = true;
      mTask->WorkerShuttingDown();
    }
    return true;
  }

  WorkerPrivate* GetWorkerPrivate() const { return mWorkerPrivate; }

 private:
  WorkerPrivate* mWorkerPrivate;
  RefPtr<CreateImageBitmapFromBlob> mTask;
  bool mNotified;
};

static void AsyncCreateImageBitmapFromBlob(Promise* aPromise,
                                           nsIGlobalObject* aGlobal,
                                           Blob& aBlob,
                                           const Maybe<IntRect>& aCropRect) {
  // Let's identify the main-thread event target.
  nsCOMPtr<nsIEventTarget> mainThreadEventTarget;
  if (NS_IsMainThread()) {
    mainThreadEventTarget = aGlobal->EventTargetFor(TaskCategory::Other);
  } else {
    WorkerPrivate* workerPrivate = GetCurrentThreadWorkerPrivate();
    MOZ_ASSERT(workerPrivate);
    mainThreadEventTarget = workerPrivate->MainThreadEventTarget();
  }

  RefPtr<CreateImageBitmapFromBlob> task = CreateImageBitmapFromBlob::Create(
      aPromise, aGlobal, aBlob, aCropRect, mainThreadEventTarget);
  if (NS_WARN_IF(!task)) {
    aPromise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  NS_DispatchToCurrentThread(task);
}

/* static */ already_AddRefed<Promise> ImageBitmap::Create(
    nsIGlobalObject* aGlobal, const ImageBitmapSource& aSrc,
    const Maybe<gfx::IntRect>& aCropRect, ErrorResult& aRv) {
  MOZ_ASSERT(aGlobal);

  RefPtr<Promise> promise = Promise::Create(aGlobal, aRv);

  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  if (aCropRect.isSome() &&
      (aCropRect->Width() == 0 || aCropRect->Height() == 0)) {
    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
    return promise.forget();
  }

  RefPtr<ImageBitmap> imageBitmap;

  if (aSrc.IsHTMLImageElement()) {
    MOZ_ASSERT(
        NS_IsMainThread(),
        "Creating ImageBitmap from HTMLImageElement off the main thread.");
    imageBitmap =
        CreateInternal(aGlobal, aSrc.GetAsHTMLImageElement(), aCropRect, aRv);
  } else if (aSrc.IsHTMLVideoElement()) {
    MOZ_ASSERT(
        NS_IsMainThread(),
        "Creating ImageBitmap from HTMLVideoElement off the main thread.");
    imageBitmap =
        CreateInternal(aGlobal, aSrc.GetAsHTMLVideoElement(), aCropRect, aRv);
  } else if (aSrc.IsHTMLCanvasElement()) {
    MOZ_ASSERT(
        NS_IsMainThread(),
        "Creating ImageBitmap from HTMLCanvasElement off the main thread.");
    imageBitmap =
        CreateInternal(aGlobal, aSrc.GetAsHTMLCanvasElement(), aCropRect, aRv);
  } else if (aSrc.IsImageData()) {
    imageBitmap =
        CreateInternal(aGlobal, aSrc.GetAsImageData(), aCropRect, aRv);
  } else if (aSrc.IsCanvasRenderingContext2D()) {
    MOZ_ASSERT(NS_IsMainThread(),
               "Creating ImageBitmap from CanvasRenderingContext2D off the "
               "main thread.");
    imageBitmap = CreateInternal(aGlobal, aSrc.GetAsCanvasRenderingContext2D(),
                                 aCropRect, aRv);
  } else if (aSrc.IsImageBitmap()) {
    imageBitmap =
        CreateInternal(aGlobal, aSrc.GetAsImageBitmap(), aCropRect, aRv);
  } else if (aSrc.IsBlob()) {
    AsyncCreateImageBitmapFromBlob(promise, aGlobal, aSrc.GetAsBlob(),
                                   aCropRect);
    return promise.forget();
  } else {
    aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
    return nullptr;
  }

  if (!aRv.Failed()) {
    AsyncFulfillImageBitmapPromise(promise, imageBitmap);
  }

  return promise.forget();
}

/*static*/ JSObject* ImageBitmap::ReadStructuredClone(
    JSContext* aCx, JSStructuredCloneReader* aReader, nsIGlobalObject* aParent,
    const nsTArray<RefPtr<DataSourceSurface>>& aClonedSurfaces,
    uint32_t aIndex) {
  MOZ_ASSERT(aCx);
  MOZ_ASSERT(aReader);
  // aParent might be null.

  uint32_t picRectX_;
  uint32_t picRectY_;
  uint32_t picRectWidth_;
  uint32_t picRectHeight_;
  uint32_t alphaType_;
  uint32_t isCroppingAreaOutSideOfSourceImage_;
  uint32_t writeOnly;
  uint32_t dummy;

  if (!JS_ReadUint32Pair(aReader, &picRectX_, &picRectY_) ||
      !JS_ReadUint32Pair(aReader, &picRectWidth_, &picRectHeight_) ||
      !JS_ReadUint32Pair(aReader, &alphaType_,
                         &isCroppingAreaOutSideOfSourceImage_) ||
      !JS_ReadUint32Pair(aReader, &writeOnly, &dummy)) {
    return nullptr;
  }

  MOZ_ASSERT(dummy == 0);

  int32_t picRectX = BitwiseCast<int32_t>(picRectX_);
  int32_t picRectY = BitwiseCast<int32_t>(picRectY_);
  int32_t picRectWidth = BitwiseCast<int32_t>(picRectWidth_);
  int32_t picRectHeight = BitwiseCast<int32_t>(picRectHeight_);
  const auto alphaType = BitwiseCast<gfxAlphaType>(alphaType_);

  // Create a new ImageBitmap.
  MOZ_ASSERT(!aClonedSurfaces.IsEmpty());
  MOZ_ASSERT(aIndex < aClonedSurfaces.Length());

  // RefPtr<ImageBitmap> needs to go out of scope before toObjectOrNull() is
  // called because the static analysis thinks dereferencing XPCOM objects
  // can GC (because in some cases it can!), and a return statement with a
  // JSObject* type means that JSObject* is on the stack as a raw pointer
  // while destructors are running.
  JS::Rooted<JS::Value> value(aCx);
  {
#ifdef FUZZING
    if (aIndex >= aClonedSurfaces.Length()) {
      return nullptr;
    }
#endif
    RefPtr<layers::Image> img = CreateImageFromSurface(aClonedSurfaces[aIndex]);
    RefPtr<ImageBitmap> imageBitmap = new ImageBitmap(aParent, img, !!writeOnly, alphaType);

    imageBitmap->mIsCroppingAreaOutSideOfSourceImage =
        isCroppingAreaOutSideOfSourceImage_;

    ErrorResult error;
    imageBitmap->SetPictureRect(
        IntRect(picRectX, picRectY, picRectWidth, picRectHeight), error);
    if (NS_WARN_IF(error.Failed())) {
      error.SuppressException();
      return nullptr;
    }

    if (!GetOrCreateDOMReflector(aCx, imageBitmap, &value)) {
      return nullptr;
    }

    imageBitmap->mAllocatedImageData = true;
  }

  return &(value.toObject());
}

/*static*/ bool ImageBitmap::WriteStructuredClone(
    JSStructuredCloneWriter* aWriter,
    nsTArray<RefPtr<DataSourceSurface>>& aClonedSurfaces,
    ImageBitmap* aImageBitmap) {
  MOZ_ASSERT(aWriter);
  MOZ_ASSERT(aImageBitmap);

  const uint32_t picRectX = BitwiseCast<uint32_t>(aImageBitmap->mPictureRect.x);
  const uint32_t picRectY = BitwiseCast<uint32_t>(aImageBitmap->mPictureRect.y);
  const uint32_t picRectWidth =
      BitwiseCast<uint32_t>(aImageBitmap->mPictureRect.width);
  const uint32_t picRectHeight =
      BitwiseCast<uint32_t>(aImageBitmap->mPictureRect.height);
  const uint32_t alphaType = BitwiseCast<uint32_t>(aImageBitmap->mAlphaType);
  const uint32_t isCroppingAreaOutSideOfSourceImage =
      aImageBitmap->mIsCroppingAreaOutSideOfSourceImage ? 1 : 0;

  // Indexing the cloned surfaces and send the index to the receiver.
  uint32_t index = aClonedSurfaces.Length();

  if (NS_WARN_IF(!JS_WriteUint32Pair(aWriter, SCTAG_DOM_IMAGEBITMAP, index)) ||
      NS_WARN_IF(!JS_WriteUint32Pair(aWriter, picRectX, picRectY)) ||
      NS_WARN_IF(!JS_WriteUint32Pair(aWriter, picRectWidth, picRectHeight)) ||
      NS_WARN_IF(!JS_WriteUint32Pair(aWriter, alphaType,
                                     isCroppingAreaOutSideOfSourceImage)) ||
      NS_WARN_IF(!JS_WriteUint32Pair(aWriter, aImageBitmap->mWriteOnly, 0))) {
    return false;
  }

  RefPtr<SourceSurface> surface = aImageBitmap->mData->GetAsSourceSurface();
  RefPtr<DataSourceSurface> snapshot = surface->GetDataSurface();
  RefPtr<DataSourceSurface> dstDataSurface;
  {
    // DataSourceSurfaceD2D1::GetStride() will call EnsureMapped implicitly and
    // won't Unmap after exiting function. So instead calling GetStride()
    // directly, using ScopedMap to get stride.
    DataSourceSurface::ScopedMap map(snapshot, DataSourceSurface::READ);
    dstDataSurface = Factory::CreateDataSourceSurfaceWithStride(
        snapshot->GetSize(), snapshot->GetFormat(), map.GetStride(), true);
  }
  if (NS_WARN_IF(!dstDataSurface)) {
    return false;
  }
  Factory::CopyDataSourceSurface(snapshot, dstDataSurface);
  aClonedSurfaces.AppendElement(dstDataSurface);
  return true;
}

// ImageBitmap extensions.
ImageBitmapFormat ImageBitmap::FindOptimalFormat(
    const Optional<Sequence<ImageBitmapFormat>>& aPossibleFormats,
    ErrorResult& aRv) {
  if (!mDataWrapper) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return ImageBitmapFormat::EndGuard_;
  }

  ImageBitmapFormat platformFormat = mDataWrapper->GetFormat();

  if (!aPossibleFormats.WasPassed() ||
      aPossibleFormats.Value().Contains(platformFormat)) {
    return platformFormat;
  } else {
    // If no matching is found, FindBestMatchingFromat() returns
    // ImageBitmapFormat::EndGuard_ and we throw an exception.
    ImageBitmapFormat optimalFormat =
        FindBestMatchingFromat(platformFormat, aPossibleFormats.Value());

    if (optimalFormat == ImageBitmapFormat::EndGuard_) {
      aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
    }

    return optimalFormat;
  }
}

int32_t ImageBitmap::MappedDataLength(ImageBitmapFormat aFormat,
                                      ErrorResult& aRv) {
  if (!mDataWrapper) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return 0;
  }

  if (aFormat == mDataWrapper->GetFormat()) {
    return mDataWrapper->GetBufferLength();
  } else {
    return CalculateImageBufferSize(aFormat, Width(), Height());
  }
}

template <typename T>
class MapDataIntoBufferSource {
 protected:
  MapDataIntoBufferSource(JSContext* aCx, Promise* aPromise,
                          ImageBitmap* aImageBitmap, const T& aBuffer,
                          int32_t aOffset, ImageBitmapFormat aFormat)
      : mPromise(aPromise),
        mImageBitmap(aImageBitmap),
        mBuffer(aCx, aBuffer.Obj()),
        mOffset(aOffset),
        mFormat(aFormat) {
    MOZ_ASSERT(mPromise);
    MOZ_ASSERT(JS_IsArrayBufferObject(mBuffer) ||
               JS_IsArrayBufferViewObject(mBuffer));
  }

  virtual ~MapDataIntoBufferSource() = default;

  void DoMapDataIntoBufferSource() {
    ErrorResult error;

    if (!mImageBitmap->mDataWrapper) {
      error.ThrowWithCustomCleanup(NS_ERROR_NOT_AVAILABLE);
      mPromise->MaybeReject(error);
      return;
    }

    // Prepare destination buffer.
    uint8_t* bufferData = nullptr;
    uint32_t bufferLength = 0;
    bool isSharedMemory = false;
    if (JS_IsArrayBufferObject(mBuffer)) {
      js::GetArrayBufferLengthAndData(mBuffer, &bufferLength, &isSharedMemory,
                                      &bufferData);
    } else if (JS_IsArrayBufferViewObject(mBuffer)) {
      js::GetArrayBufferViewLengthAndData(mBuffer, &bufferLength,
                                          &isSharedMemory, &bufferData);
    } else {
      error.ThrowWithCustomCleanup(NS_ERROR_NOT_IMPLEMENTED);
      mPromise->MaybeReject(error);
      return;
    }

    if (NS_WARN_IF(!bufferData) || NS_WARN_IF(!bufferLength)) {
      error.ThrowWithCustomCleanup(NS_ERROR_NOT_AVAILABLE);
      mPromise->MaybeReject(error);
      return;
    }

    // Check length.
    const int32_t neededBufferLength =
        mImageBitmap->MappedDataLength(mFormat, error);

    if (((int32_t)bufferLength - mOffset) < neededBufferLength) {
      error.ThrowWithCustomCleanup(NS_ERROR_DOM_INDEX_SIZE_ERR);
      mPromise->MaybeReject(error);
      return;
    }

    // Call ImageBitmapFormatUtils.
    UniquePtr<ImagePixelLayout> layout =
        mImageBitmap->mDataWrapper->MapDataInto(bufferData, mOffset,
                                                bufferLength, mFormat, error);

    if (NS_WARN_IF(!layout)) {
      mPromise->MaybeReject(error);
      return;
    }

    mPromise->MaybeResolve(*layout);
  }

  RefPtr<Promise> mPromise;
  RefPtr<ImageBitmap> mImageBitmap;
  JS::PersistentRooted<JSObject*> mBuffer;
  int32_t mOffset;
  ImageBitmapFormat mFormat;
};

template <typename T>
class MapDataIntoBufferSourceTask final : public Runnable,
                                          public MapDataIntoBufferSource<T> {
 public:
  MapDataIntoBufferSourceTask(JSContext* aCx, Promise* aPromise,
                              ImageBitmap* aImageBitmap, const T& aBuffer,
                              int32_t aOffset, ImageBitmapFormat aFormat)
      : Runnable("dom::MapDataIntoBufferSourceTask"),
        MapDataIntoBufferSource<T>(aCx, aPromise, aImageBitmap, aBuffer,
                                   aOffset, aFormat) {}

  virtual ~MapDataIntoBufferSourceTask() = default;

  NS_IMETHOD Run() override {
    MapDataIntoBufferSource<T>::DoMapDataIntoBufferSource();
    return NS_OK;
  }
};

template <typename T>
class MapDataIntoBufferSourceWorkerTask final
    : public WorkerSameThreadRunnable,
      public MapDataIntoBufferSource<T> {
 public:
  MapDataIntoBufferSourceWorkerTask(JSContext* aCx, Promise* aPromise,
                                    ImageBitmap* aImageBitmap, const T& aBuffer,
                                    int32_t aOffset, ImageBitmapFormat aFormat)
      : WorkerSameThreadRunnable(GetCurrentThreadWorkerPrivate()),
        MapDataIntoBufferSource<T>(aCx, aPromise, aImageBitmap, aBuffer,
                                   aOffset, aFormat) {}

  virtual ~MapDataIntoBufferSourceWorkerTask() = default;

  bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
    MapDataIntoBufferSource<T>::DoMapDataIntoBufferSource();
    return true;
  }
};

void AsyncMapDataIntoBufferSource(JSContext* aCx, Promise* aPromise,
                                  ImageBitmap* aImageBitmap,
                                  const ArrayBufferViewOrArrayBuffer& aBuffer,
                                  int32_t aOffset, ImageBitmapFormat aFormat) {
  MOZ_ASSERT(aCx);
  MOZ_ASSERT(aPromise);
  MOZ_ASSERT(aImageBitmap);

  if (NS_IsMainThread()) {
    nsCOMPtr<nsIRunnable> task;

    if (aBuffer.IsArrayBuffer()) {
      const ArrayBuffer& buffer = aBuffer.GetAsArrayBuffer();
      task = new MapDataIntoBufferSourceTask<ArrayBuffer>(
          aCx, aPromise, aImageBitmap, buffer, aOffset, aFormat);
    } else if (aBuffer.IsArrayBufferView()) {
      const ArrayBufferView& bufferView = aBuffer.GetAsArrayBufferView();
      task = new MapDataIntoBufferSourceTask<ArrayBufferView>(
          aCx, aPromise, aImageBitmap, bufferView, aOffset, aFormat);
    }

    NS_DispatchToCurrentThread(task);  // Actually, to the main-thread.
  } else {
    RefPtr<WorkerSameThreadRunnable> task;

    if (aBuffer.IsArrayBuffer()) {
      const ArrayBuffer& buffer = aBuffer.GetAsArrayBuffer();
      task = new MapDataIntoBufferSourceWorkerTask<ArrayBuffer>(
          aCx, aPromise, aImageBitmap, buffer, aOffset, aFormat);
    } else if (aBuffer.IsArrayBufferView()) {
      const ArrayBufferView& bufferView = aBuffer.GetAsArrayBufferView();
      task = new MapDataIntoBufferSourceWorkerTask<ArrayBufferView>(
          aCx, aPromise, aImageBitmap, bufferView, aOffset, aFormat);
    }

    task->Dispatch();  // Actually, to the current worker-thread.
  }
}

already_AddRefed<Promise> ImageBitmap::MapDataInto(
    JSContext* aCx, ImageBitmapFormat aFormat,
    const ArrayBufferViewOrArrayBuffer& aBuffer, int32_t aOffset,
    ErrorResult& aRv) {
  MOZ_ASSERT(aCx, "No JSContext while calling ImageBitmap::MapDataInto().");

  RefPtr<Promise> promise = Promise::Create(mParent, aRv);

  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  if (!mDataWrapper) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return promise.forget();
  }

  // Check for cases that should throws.
  // Case 1:
  // If image bitmap was cropped to the source rectangle so that it contains any
  // transparent black pixels (cropping area is outside of the source image),
  // then reject promise with IndexSizeError and abort these steps.
  if (mIsCroppingAreaOutSideOfSourceImage) {
    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
    return promise.forget();
  }

  // Case 2:
  // If the image bitmap is going to be accessed in YUV422/YUV422 series with a
  // cropping area starts at an odd x or y coordinate.
  if (aFormat == ImageBitmapFormat::YUV422P ||
      aFormat == ImageBitmapFormat::YUV420P ||
      aFormat == ImageBitmapFormat::YUV420SP_NV12 ||
      aFormat == ImageBitmapFormat::YUV420SP_NV21) {
    if ((mPictureRect.x & 1) || (mPictureRect.y & 1)) {
      aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
      return promise.forget();
    }
  }

  AsyncMapDataIntoBufferSource(aCx, promise, this, aBuffer, aOffset, aFormat);
  return promise.forget();
}

// ImageBitmapFactories extensions.
static SurfaceFormat ImageFormatToSurfaceFromat(
    mozilla::dom::ImageBitmapFormat aFormat) {
  switch (aFormat) {
    case ImageBitmapFormat::RGBA32:
      return SurfaceFormat::R8G8B8A8;
    case ImageBitmapFormat::BGRA32:
      return SurfaceFormat::B8G8R8A8;
    case ImageBitmapFormat::RGB24:
      return SurfaceFormat::R8G8B8;
    case ImageBitmapFormat::BGR24:
      return SurfaceFormat::B8G8R8;
    case ImageBitmapFormat::GRAY8:
      return SurfaceFormat::A8;
    case ImageBitmapFormat::HSV:
      return SurfaceFormat::HSV;
    case ImageBitmapFormat::Lab:
      return SurfaceFormat::Lab;
    case ImageBitmapFormat::DEPTH:
      return SurfaceFormat::Depth;
    default:
      return SurfaceFormat::UNKNOWN;
  }
}

static already_AddRefed<layers::Image> CreateImageFromBufferSourceRawData(
    const uint8_t* aBufferData, uint32_t aBufferLength,
    mozilla::dom::ImageBitmapFormat aFormat,
    const Sequence<ChannelPixelLayout>& aLayout) {
  MOZ_ASSERT(aBufferData);
  MOZ_ASSERT(aBufferLength > 0);

  switch (aFormat) {
    case ImageBitmapFormat::RGBA32:
    case ImageBitmapFormat::BGRA32:
    case ImageBitmapFormat::RGB24:
    case ImageBitmapFormat::BGR24:
    case ImageBitmapFormat::GRAY8:
    case ImageBitmapFormat::HSV:
    case ImageBitmapFormat::Lab:
    case ImageBitmapFormat::DEPTH: {
      const nsTArray<ChannelPixelLayout>& channels = aLayout;
      MOZ_ASSERT(channels.Length() != 0, "Empty Channels.");

      const SurfaceFormat srcFormat = ImageFormatToSurfaceFromat(aFormat);
      const uint32_t srcStride = channels[0].mStride;
      const IntSize srcSize(channels[0].mWidth, channels[0].mHeight);

      RefPtr<DataSourceSurface> dstDataSurface =
          Factory::CreateDataSourceSurfaceWithStride(srcSize, srcFormat,
                                                     srcStride);

      if (NS_WARN_IF(!dstDataSurface)) {
        return nullptr;
      }

      // Copy the raw data into the newly created DataSourceSurface.
      DataSourceSurface::ScopedMap dstMap(dstDataSurface,
                                          DataSourceSurface::WRITE);
      if (NS_WARN_IF(!dstMap.IsMapped())) {
        return nullptr;
      }

      const uint8_t* srcBufferPtr = aBufferData;
      uint8_t* dstBufferPtr = dstMap.GetData();

      for (int i = 0; i < srcSize.height; ++i) {
        memcpy(dstBufferPtr, srcBufferPtr, srcStride);
        srcBufferPtr += srcStride;
        dstBufferPtr += dstMap.GetStride();
      }

      // Create an Image from the BGRA SourceSurface.
      RefPtr<SourceSurface> surface = dstDataSurface;
      RefPtr<layers::Image> image = CreateImageFromSurface(surface);

      if (NS_WARN_IF(!image)) {
        return nullptr;
      }

      return image.forget();
    }
    case ImageBitmapFormat::YUV444P:
    case ImageBitmapFormat::YUV422P:
    case ImageBitmapFormat::YUV420P:
    case ImageBitmapFormat::YUV420SP_NV12:
    case ImageBitmapFormat::YUV420SP_NV21: {
      // Prepare the PlanarYCbCrData.
      const ChannelPixelLayout& yLayout = aLayout[0];
      const ChannelPixelLayout& uLayout =
          aFormat != ImageBitmapFormat::YUV420SP_NV21 ? aLayout[1] : aLayout[2];
      const ChannelPixelLayout& vLayout =
          aFormat != ImageBitmapFormat::YUV420SP_NV21 ? aLayout[2] : aLayout[1];

      layers::PlanarYCbCrData data;

      // Luminance buffer
      data.mYChannel = const_cast<uint8_t*>(aBufferData + yLayout.mOffset);
      data.mYStride = yLayout.mStride;
      data.mYSize = gfx::IntSize(yLayout.mWidth, yLayout.mHeight);
      data.mYSkip = yLayout.mSkip;

      // Chroma buffers
      data.mCbChannel = const_cast<uint8_t*>(aBufferData + uLayout.mOffset);
      data.mCrChannel = const_cast<uint8_t*>(aBufferData + vLayout.mOffset);
      data.mCbCrStride = uLayout.mStride;
      data.mCbCrSize = gfx::IntSize(uLayout.mWidth, uLayout.mHeight);
      data.mCbSkip = uLayout.mSkip;
      data.mCrSkip = vLayout.mSkip;

      // Picture rectangle.
      // We set the picture rectangle to exactly the size of the source image to
      // keep the full original data.
      data.mPicX = 0;
      data.mPicY = 0;
      data.mPicSize = data.mYSize;

      // Create a layers::Image and set data.
      if (aFormat == ImageBitmapFormat::YUV444P ||
          aFormat == ImageBitmapFormat::YUV422P ||
          aFormat == ImageBitmapFormat::YUV420P) {
        RefPtr<layers::PlanarYCbCrImage> image =
            new layers::RecyclingPlanarYCbCrImage(
                new layers::BufferRecycleBin());

        if (NS_WARN_IF(!image)) {
          return nullptr;
        }

        // Set Data.
        if (NS_WARN_IF(!image->CopyData(data))) {
          return nullptr;
        }

        return image.forget();
      } else {
        RefPtr<layers::NVImage> image = new layers::NVImage();

        if (NS_WARN_IF(!image)) {
          return nullptr;
        }

        // Set Data.
        if (NS_WARN_IF(!image->SetData(data))) {
          return nullptr;
        }

        return image.forget();
      }
    }
    default:
      return nullptr;
  }
}

/*
 * This is a synchronous task.
 * This class is used to create a layers::CairoImage from raw data in the main
 * thread. While creating an ImageBitmap from an BufferSource, we need to create
 * a SouceSurface from the BufferSource raw data and then set the SourceSurface
 * into a layers::CairoImage. However, the layers::CairoImage asserts the
 * setting operation in the main thread, so if we are going to create an
 * ImageBitmap from an BufferSource off the main thread, we post an event to the
 * main thread to create a layers::CairoImage from an BufferSource raw data.
 *
 * TODO: Once the layers::CairoImage is constructible off the main thread, which
 *       means the SouceSurface could be released anywhere, we do not need this
 *       task anymore.
 */
class CreateImageFromBufferSourceRawDataInMainThreadSyncTask final
    : public WorkerMainThreadRunnable {
 public:
  CreateImageFromBufferSourceRawDataInMainThreadSyncTask(
      const uint8_t* aBuffer, uint32_t aBufferLength,
      mozilla::dom::ImageBitmapFormat aFormat,
      const Sequence<ChannelPixelLayout>& aLayout,
      /*output*/ layers::Image** aImage)
      : WorkerMainThreadRunnable(
            GetCurrentThreadWorkerPrivate(),
            NS_LITERAL_CSTRING("ImageBitmap-extensions :: Create Image from "
                               "BufferSource Raw Data")),
        mImage(aImage),
        mBuffer(aBuffer),
        mBufferLength(aBufferLength),
        mFormat(aFormat),
        mLayout(aLayout) {
    MOZ_ASSERT(!(*aImage),
               "Don't pass an existing Image into "
               "CreateImageFromBufferSourceRawDataInMainThreadSyncTask.");
  }

  bool MainThreadRun() override {
    RefPtr<layers::Image> image = CreateImageFromBufferSourceRawData(
        mBuffer, mBufferLength, mFormat, mLayout);

    if (NS_WARN_IF(!image)) {
      return true;
    }

    image.forget(mImage);

    return true;
  }

 private:
  layers::Image** mImage;
  const uint8_t* mBuffer;
  uint32_t mBufferLength;
  mozilla::dom::ImageBitmapFormat mFormat;
  const Sequence<ChannelPixelLayout>& mLayout;
};

/*static*/ already_AddRefed<Promise> ImageBitmap::Create(
    nsIGlobalObject* aGlobal, const ImageBitmapSource& aBuffer, int32_t aOffset,
    int32_t aLength, mozilla::dom::ImageBitmapFormat aFormat,
    const Sequence<ChannelPixelLayout>& aLayout, ErrorResult& aRv) {
  MOZ_ASSERT(aGlobal);

  RefPtr<Promise> promise = Promise::Create(aGlobal, aRv);

  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  uint8_t* bufferData = nullptr;
  uint32_t bufferLength = 0;

  if (aBuffer.IsArrayBuffer()) {
    const ArrayBuffer& buffer = aBuffer.GetAsArrayBuffer();
    buffer.ComputeLengthAndData();
    bufferData = buffer.Data();
    bufferLength = buffer.Length();
  } else if (aBuffer.IsArrayBufferView()) {
    const ArrayBufferView& bufferView = aBuffer.GetAsArrayBufferView();
    bufferView.ComputeLengthAndData();
    bufferData = bufferView.Data();
    bufferLength = bufferView.Length();
  } else {
    aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
    return promise.forget();
  }

  MOZ_ASSERT(bufferData && bufferLength > 0,
             "Cannot read data from BufferSource.");

  // Check the buffer.
  if (((uint32_t)(aOffset + aLength) > bufferLength)) {
    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
    return promise.forget();
  }

  // Create and Crop the raw data into a layers::Image
  RefPtr<layers::Image> data;
  if (NS_IsMainThread()) {
    data = CreateImageFromBufferSourceRawData(bufferData + aOffset,
                                              bufferLength, aFormat, aLayout);
  } else {
    RefPtr<CreateImageFromBufferSourceRawDataInMainThreadSyncTask> task =
        new CreateImageFromBufferSourceRawDataInMainThreadSyncTask(
            bufferData + aOffset, bufferLength, aFormat, aLayout,
            getter_AddRefs(data));
    task->Dispatch(Terminating, aRv);
    if (aRv.Failed()) {
      return promise.forget();
    }
  }

  if (NS_WARN_IF(!data)) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return promise.forget();
  }

  // Create an ImageBimtap.
  // Assume the data from an external buffer is not alpha-premultiplied.
  RefPtr<ImageBitmap> imageBitmap =
      new ImageBitmap(aGlobal, data, false /* write-only */,
                      gfxAlphaType::NonPremult);

  imageBitmap->mAllocatedImageData = true;

  // We don't need to call SetPictureRect() here because there is no cropping
  // supported and the ImageBitmap's mPictureRect is the size of the source
  // image in default

  // We don't need to set mIsCroppingAreaOutSideOfSourceImage here because there
  // is no cropping supported and the mIsCroppingAreaOutSideOfSourceImage is
  // false in default.

  AsyncFulfillImageBitmapPromise(promise, imageBitmap);

  return promise.forget();
}

size_t ImageBitmap::GetAllocatedSize() const {
  if (!mAllocatedImageData) {
    return 0;
  }

  // Calculate how many bytes are used.
  if (mData->GetFormat() == mozilla::ImageFormat::PLANAR_YCBCR) {
    return mData->AsPlanarYCbCrImage()->GetDataSize();
  }

  if (mData->GetFormat() == mozilla::ImageFormat::NV_IMAGE) {
    return mData->AsNVImage()->GetBufferSize();
  }

  RefPtr<SourceSurface> surface = mData->GetAsSourceSurface();
  const int bytesPerPixel = BytesPerPixel(surface->GetFormat());
  return surface->GetSize().height * surface->GetSize().width * bytesPerPixel;
}

size_t BindingJSObjectMallocBytes(ImageBitmap* aBitmap) {
  return aBitmap->GetAllocatedSize();
}

/* static */ already_AddRefed<CreateImageBitmapFromBlob>
CreateImageBitmapFromBlob::Create(Promise* aPromise, nsIGlobalObject* aGlobal,
                                  Blob& aBlob, const Maybe<IntRect>& aCropRect,
                                  nsIEventTarget* aMainThreadEventTarget) {
  // Get the internal stream of the blob.
  nsCOMPtr<nsIInputStream> stream;
  ErrorResult error;
  aBlob.Impl()->CreateInputStream(getter_AddRefs(stream), error);
  if (NS_WARN_IF(error.Failed())) {
    return nullptr;
  }

  // Get the MIME type string of the blob.
  // The type will be checked in the DecodeImageAsync() method.
  nsAutoString mimeTypeUTF16;
  aBlob.Impl()->GetType(mimeTypeUTF16);
  NS_ConvertUTF16toUTF8 mimeType(mimeTypeUTF16);

  RefPtr<CreateImageBitmapFromBlob> task = new CreateImageBitmapFromBlob(
      aPromise, aGlobal, stream.forget(), mimeType, aCropRect,
      aMainThreadEventTarget);

  // Nothing to do for the main-thread.
  if (NS_IsMainThread()) {
    return task.forget();
  }

  // Let's use a WorkerHolder to keep the worker alive if this is not the
  // main-thread.
  WorkerPrivate* workerPrivate = GetCurrentThreadWorkerPrivate();
  MOZ_ASSERT(workerPrivate);

  UniquePtr<CreateImageBitmapFromBlobHolder> holder(
      new CreateImageBitmapFromBlobHolder(workerPrivate, task));

  if (!holder->HoldWorker(workerPrivate, Terminating)) {
    return nullptr;
  }

  task->mWorkerHolder = Move(holder);
  return task.forget();
}

nsresult CreateImageBitmapFromBlob::StartDecodeAndCropBlob() {
  MOZ_ASSERT(IsCurrentThread());

  // Workers.
  if (!NS_IsMainThread()) {
    RefPtr<CreateImageBitmapFromBlob> self = this;
    nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
        "CreateImageBitmapFromBlob::DecodeAndCropBlob", [self]() {
          nsresult rv = self->DecodeAndCropBlob();
          if (NS_WARN_IF(NS_FAILED(rv))) {
            self->DecodeAndCropBlobCompletedMainThread(nullptr, rv);
          }
        });

    return mMainThreadEventTarget->Dispatch(r.forget());
  }

  // Main-thread.
  return DecodeAndCropBlob();
}

nsresult CreateImageBitmapFromBlob::DecodeAndCropBlob() {
  MOZ_ASSERT(NS_IsMainThread());

  // Get the Component object.
  nsCOMPtr<imgITools> imgtool = do_GetService(NS_IMGTOOLS_CID);
  if (NS_WARN_IF(!imgtool)) {
    return NS_ERROR_FAILURE;
  }

  // Decode image.
  nsCOMPtr<imgIContainer> imgContainer;
  nsresult rv = imgtool->DecodeImageAsync(mInputStream, mMimeType, this,
                                          mMainThreadEventTarget);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

NS_IMETHODIMP
CreateImageBitmapFromBlob::OnImageReady(imgIContainer* aImgContainer,
                                        nsresult aStatus) {
  MOZ_ASSERT(NS_IsMainThread());

  if (NS_FAILED(aStatus)) {
    DecodeAndCropBlobCompletedMainThread(nullptr, aStatus);
    return NS_OK;
  }

  MOZ_ASSERT(aImgContainer);

  // Get the surface out.
  uint32_t frameFlags =
      imgIContainer::FLAG_SYNC_DECODE | imgIContainer::FLAG_WANT_DATA_SURFACE;
  uint32_t whichFrame = imgIContainer::FRAME_FIRST;
  RefPtr<SourceSurface> surface =
      aImgContainer->GetFrame(whichFrame, frameFlags);

  if (NS_WARN_IF(!surface)) {
    DecodeAndCropBlobCompletedMainThread(nullptr, NS_ERROR_FAILURE);
    return NS_OK;
  }

  // Store the sourceSize value for the DecodeAndCropBlobCompletedMainThread
  // call.
  mSourceSize = surface->GetSize();

  // Crop the source surface if needed.
  RefPtr<SourceSurface> croppedSurface = surface;

  if (mCropRect.isSome()) {
    // The blob is just decoded into a RasterImage and not optimized yet, so the
    // _surface_ we get is a DataSourceSurface which wraps the RasterImage's
    // raw buffer.
    //
    // The _surface_ might already be optimized so that its type is not
    // SurfaceType::DATA. However, we could keep using the generic cropping and
    // copying since the decoded buffer is only used in this ImageBitmap so we
    // should crop it to save memory usage.
    //
    // TODO: Bug1189632 is going to refactor this create-from-blob part to
    //       decode the blob off the main thread. Re-check if we should do
    //       cropping at this moment again there.
    RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
    croppedSurface = CropAndCopyDataSourceSurface(dataSurface, mCropRect.ref());
    mCropRect->MoveTo(0, 0);
  }

  if (NS_WARN_IF(!croppedSurface)) {
    DecodeAndCropBlobCompletedMainThread(nullptr, NS_ERROR_FAILURE);
    return NS_OK;
  }

  // Create an Image from the source surface.
  RefPtr<layers::Image> image = CreateImageFromSurface(croppedSurface);

  if (NS_WARN_IF(!image)) {
    DecodeAndCropBlobCompletedMainThread(nullptr, NS_ERROR_FAILURE);
    return NS_OK;
  }

  DecodeAndCropBlobCompletedMainThread(image, NS_OK);
  return NS_OK;
}

void CreateImageBitmapFromBlob::DecodeAndCropBlobCompletedMainThread(
    layers::Image* aImage, nsresult aStatus) {
  MOZ_ASSERT(NS_IsMainThread());

  if (!IsCurrentThread()) {
    MutexAutoLock lock(mMutex);

    if (!mWorkerHolder) {
      // The worker is already gone.
      return;
    }

    RefPtr<CreateImageBitmapFromBlobRunnable> r =
        new CreateImageBitmapFromBlobRunnable(mWorkerHolder->GetWorkerPrivate(),
                                              this, aImage, aStatus);
    r->Dispatch();
    return;
  }

  DecodeAndCropBlobCompletedOwningThread(aImage, aStatus);
}

void CreateImageBitmapFromBlob::DecodeAndCropBlobCompletedOwningThread(
    layers::Image* aImage, nsresult aStatus) {
  MOZ_ASSERT(IsCurrentThread());

  if (!mPromise) {
    // The worker is going to be released soon. No needs to continue.
    return;
  }

  // Let's release what has to be released on the owning thread.
  auto raii = MakeScopeExit([&] {
    // Doing this we also release the worker.
    mWorkerHolder = nullptr;

    mPromise = nullptr;
    mGlobalObject = nullptr;
  });

  if (NS_WARN_IF(NS_FAILED(aStatus))) {
    mPromise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  // Create ImageBitmap object.
  RefPtr<ImageBitmap> imageBitmap = new ImageBitmap(mGlobalObject, aImage,
                                                    false /* write-only */);

  // Set mIsCroppingAreaOutSideOfSourceImage.
  imageBitmap->SetIsCroppingAreaOutSideOfSourceImage(mSourceSize,
                                                     mOriginalCropRect);

  if (mCropRect.isSome()) {
    ErrorResult rv;
    imageBitmap->SetPictureRect(mCropRect.ref(), rv);

    if (rv.Failed()) {
      mPromise->MaybeReject(rv);
      return;
    }
  }

  imageBitmap->mAllocatedImageData = true;

  mPromise->MaybeResolve(imageBitmap);
}

void CreateImageBitmapFromBlob::WorkerShuttingDown() {
  MOZ_ASSERT(IsCurrentThread());

  MutexAutoLock lock(mMutex);

  // Let's release all the non-thread-safe objects now.
  mWorkerHolder = nullptr;
  mPromise = nullptr;
  mGlobalObject = nullptr;
}

}  // namespace dom
}  // namespace mozilla