Make ImageBitmap Transferable

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 "config.h"
 #include "core/frame/ImageBitmap.h"
 
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/ImageData.h"
@@ skipping 163 matching lines @@
     IntRect normalizedCropRect = normalizeRect(cropRect);
     return adoptRefWillBeNoop(new ImageBitmap(bitmap, normalizedCropRect));
 }
 
 PassRefPtrWillBeRawPtr<ImageBitmap> ImageBitmap::create(Image* image, const IntRect& cropRect)
 {
     IntRect normalizedCropRect = normalizeRect(cropRect);
     return adoptRefWillBeNoop(new ImageBitmap(image, normalizedCropRect));
 }
 
+void ImageBitmap::neuter()
+{
+    if (m_imageElement)
+        m_imageElement.clear();
+    if (m_bitmap)
+        m_bitmap.clear();
+}
+
+PassRefPtrWillBeRawPtr<ImageBitmap> ImageBitmap::transfer()
+{
+    return adoptRef(new ImageBitmap(this, m_cropRect));

[Justin Novosad, 2015/10/23 15:01:22]

I don't think this is oilpan safe. The adoptRef should be gone in oilpan mode. I
think what you want here is adoptRefWillBeNoop.

+}
+
 void ImageBitmap::notifyImageSourceChanged()
 {
     m_bitmap = cropImage(m_imageElement->cachedImage()->image(), m_cropRect);
     m_bitmapOffset = IntPoint();
     m_imageElement = nullptr;
 }
 
 PassRefPtr<Image> ImageBitmap::bitmapImage() const
 {
     ASSERT((m_imageElement || m_bitmap || !m_bitmapRect.width() || !m_bitmapRect.height()) && (!m_imageElement || !m_bitmap));
@@ skipping 26 matching lines @@
     return FloatSize(width(), height());
 }
 
 DEFINE_TRACE(ImageBitmap)
 {
     visitor->trace(m_imageElement);
     ImageLoaderClient::trace(visitor);
 }
 
 } // namespace blink