Replace RefPtrs with raw pointers (imageFromNode in Editor.cpp)

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 110 matching lines @@
 {
     if (size.isEmpty())
         return false;
     if (size.width() * size.height() > MaxCanvasArea)
         return false;
     if (size.width() > MaxSkiaDim || size.height() > MaxSkiaDim)
         return false;
     return true;
 }
 
-PassRefPtr<Image> createTransparentImage(const IntSize& size)
-{
-    DCHECK(canCreateImageBuffer(size));
-    sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(size.width(), size.height());
-    surface->getCanvas()->clear(SK_ColorTRANSPARENT);
-    return StaticBitmapImage::create(fromSkSp(surface->makeImageSnapshot()));
-}
-
 } // namespace
 
 inline HTMLCanvasElement::HTMLCanvasElement(Document& document)
     : HTMLElement(canvasTag, document)
     , ContextLifecycleObserver(&document)
     , PageLifecycleObserver(document.page())
     , m_size(DefaultWidth, DefaultHeight)
     , m_ignoreReset(false)
     , m_externallyAllocatedMemory(0)
     , m_originClean(true)
@@ skipping 824 matching lines @@
 {
     DCHECK(m_context);
     if ((hasImageBuffer() && !m_imageBuffer->isAccelerated()) || m_didFailToCreateImageBuffer)
         return;
     discardImageBuffer();
     OpacityMode opacityMode = m_context->hasAlpha() ? NonOpaque : Opaque;
     m_imageBuffer = ImageBuffer::create(size(), opacityMode);
     m_didFailToCreateImageBuffer = !m_imageBuffer;
 }
 
-PassRefPtr<Image> HTMLCanvasElement::copiedImage(SourceDrawingBuffer sourceBuffer, AccelerationHint hint) const
+Image* HTMLCanvasElement::copiedImage(SourceDrawingBuffer sourceBuffer, AccelerationHint hint) const
 {
     if (!isPaintable())
         return nullptr;
     if (!m_context)
-        return createTransparentImage(size());
+        return ensureTransparentImage();
 
     bool needToUpdate = !m_copiedImage;
     // The concept of SourceDrawingBuffer is valid on only WebGL.
     if (m_context->is3d())
         needToUpdate |= m_context->paintRenderingResultsToCanvas(sourceBuffer);
     if (needToUpdate && buffer()) {
         m_copiedImage = buffer()->newImageSnapshot(hint, SnapshotReasonGetCopiedImage);
         updateExternallyAllocatedMemory();
     }
-    return m_copiedImage;
+    return m_copiedImage.get();
 }
 
 void HTMLCanvasElement::discardImageBuffer()
 {
     m_imageBuffer.reset();
     m_dirtyRect = FloatRect();
     updateExternallyAllocatedMemory();
 }
 
 void HTMLCanvasElement::clearCopiedImage()
@@ skipping 51 matching lines @@
         return nullptr;
     }
 
     if (!isPaintable()) {
         *status = InvalidSourceImageStatus;
         return nullptr;
     }
 
     if (!m_context) {
         *status = NormalSourceImageStatus;
-        return createTransparentImage(size());
+        return ensureTransparentImage();
     }
 
     if (m_context->is3d()) {
         m_context->paintRenderingResultsToCanvas(BackBuffer);
     }
 
     RefPtr<SkImage> image = buffer()->newSkImageSnapshot(hint, reason);
     if (image) {
         *status = NormalSourceImageStatus;
         return StaticBitmapImage::create(image.release());
@@ skipping 106 matching lines @@
 }
 
 bool HTMLCanvasElement::createSurfaceLayer()
 {
     DCHECK(!m_surfaceLayerBridge);
     std::unique_ptr<CanvasSurfaceLayerBridgeClient> bridgeClient = wrapUnique(new CanvasSurfaceLayerBridgeClientImpl());
     m_surfaceLayerBridge = wrapUnique(new CanvasSurfaceLayerBridge(std::move(bridgeClient)));
     return m_surfaceLayerBridge->createSurfaceLayer(this->width(), this->height());
 }
 
+Image* HTMLCanvasElement::ensureTransparentImage() const
+{
+    if (m_transparentImage && m_transparentImage->size() == size())
+        return m_transparentImage.get();
+    DCHECK(canCreateImageBuffer(size()));
+    sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(size().width(), size().height());
+    surface->getCanvas()->clear(SK_ColorTRANSPARENT);
+    m_transparentImage = StaticBitmapImage::create(fromSkSp(surface->makeImageSnapshot()));
+    return m_transparentImage.get();

[Ken Russell (switch to Gerrit), 2016/07/06 21:37:04]

This seems to introduce a bunch of caching problems. What happens if the caller
indirectly calls this method, then changes the canvas's content, and then calls
it again?

[hajimehoshi, 2016/07/07 10:53:06]

Even when the content is changed, as long as the size is not changed, the same
transparent image will be used.

+}
+
 } // namespace blink