Merge 92227 - [Chromium] Remove an unnecessary readback during accelerated

Source/WebCore/platform/graphics/skia/ImageBufferSkia.cpp

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
@@ skipping 94 matching lines @@
 }
 
 void ImageBuffer::clip(GraphicsContext* context, const FloatRect& rect) const
 {
     context->platformContext()->beginLayerClippedToImage(rect, this);
 }
 
 void ImageBuffer::draw(GraphicsContext* context, ColorSpace styleColorSpace, const FloatRect& destRect, const FloatRect& srcRect,
                        CompositeOperator op, bool useLowQualityScale)
 {
+    // Set both graphics contexts current. This looks a little weird, but is
+    // necessary since we may be drawing from an accelerated to
+    // non-accelerated context (e.g., printing), or vice versa. Note that it
+    // only works because the context is actually the same underlying context
+    // (or null), since we use one context for accelerated drawing. If that
+    // assumption changes, we'll have to revisit this code.
+    context->platformContext()->makeGrContextCurrent();
     m_context->platformContext()->makeGrContextCurrent();
-    SkDevice* srcDevice = m_context->platformContext()->canvas()->getDevice();
-    SkBitmap bitmap = srcDevice->accessBitmap(false);
-    SkAutoLockPixels bitmapLock(bitmap);
-    context->platformContext()->makeGrContextCurrent();
-    RefPtr<Image> image = BitmapImageSingleFrameSkia::create(bitmap, context == m_context);
+    RefPtr<Image> image = BitmapImageSingleFrameSkia::create(*m_data.m_platformContext.bitmap(), context == m_context);
     context->drawImage(image.get(), styleColorSpace, destRect, srcRect, op, useLowQualityScale);
 }
 
 void ImageBuffer::drawPattern(GraphicsContext* context, const FloatRect& srcRect, const AffineTransform& patternTransform,
                               const FloatPoint& phase, ColorSpace styleColorSpace, CompositeOperator op, const FloatRect& destRect)
 {
     context->platformContext()->makeGrContextCurrent();
     RefPtr<Image> image = BitmapImageSingleFrameSkia::create(*m_data.m_platformContext.bitmap(), context == m_context);
     image->drawPattern(context, srcRect, patternTransform, phase, styleColorSpace, op, destRect);
 }
@@ skipping 242 matching lines @@
 
     return ImageToDataURL(bitmap, mimeType, quality);
 }
 
 String ImageDataToDataURL(const ImageData& source, const String& mimeType, const double* quality)
 {
     return ImageToDataURL(source, mimeType, quality);
 }
 
 } // namespace WebCore