WIP: Adjust externally allocated memory when ImageBitmap is transferred

third_party/WebKit/Source/core/frame/ImageBitmap.cpp

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/ImageBitmap.h"
 
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/ImageData.h"
 #include "core/offscreencanvas/OffscreenCanvas.h"
@@ skipping 963 matching lines @@
   m_image = std::move(image);
 }
 
 PassRefPtr<StaticBitmapImage> ImageBitmap::transfer() {
   ASSERT(!isNeutered());
   m_isNeutered = true;
   m_image->transfer();
   return std::move(m_image);
 }
 
-ImageBitmap::~ImageBitmap() {}
+ImageBitmap::~ImageBitmap() {
+  if (m_image)
+    m_image->unregisterExternalAllocationWithCurrentContext();

[jbroman, 2017/04/04 15:44:56]

Is this balanced by a corresponding increase somewhere in the non-transfer case?

[Justin Novosad, 2017/04/04 16:15:15]

I think It would be cleaner to take care of register/unregister in
StaticBitmapImage constructor/destructor.

+}
 
 ImageBitmap* ImageBitmap::create(HTMLImageElement* image,
                                  Optional<IntRect> cropRect,
                                  Document* document,
                                  const ImageBitmapOptions& options) {
   return new ImageBitmap(image, cropRect, document, options);
 }
 
 ImageBitmap* ImageBitmap::create(HTMLVideoElement* video,
                                  Optional<IntRect> cropRect,
@@ skipping 41 matching lines @@
                                  uint32_t height,
                                  bool isImageBitmapPremultiplied,
                                  bool isImageBitmapOriginClean) {
   return new ImageBitmap(pixelData, width, height, isImageBitmapPremultiplied,
                          isImageBitmapOriginClean);
 }
 
 void ImageBitmap::close() {
   if (!m_image || m_isNeutered)
     return;
+  if (m_image)
+    m_image->unregisterExternalAllocationWithCurrentContext();
   m_image.clear();
   m_isNeutered = true;
 }
 
 // static
 ImageBitmap* ImageBitmap::take(ScriptPromiseResolver*, sk_sp<SkImage> image) {
   return ImageBitmap::create(StaticBitmapImage::create(std::move(image)));
 }
 
 PassRefPtr<Uint8Array> ImageBitmap::copyBitmapData(AlphaDisposition alphaOp,
@@ skipping 69 matching lines @@
 void ImageBitmap::adjustDrawRects(FloatRect* srcRect,
                                   FloatRect* dstRect) const {}
 
 FloatSize ImageBitmap::elementSize(const FloatSize&) const {
   return FloatSize(width(), height());
 }
 
 DEFINE_TRACE(ImageBitmap) {}
 
 }  // namespace blink