Eliminate deferral overhead with canvas to canvas draws

Source/platform/graphics/ImageBuffer.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 75 matching lines @@
 {
 }
 
 SkCanvas* ImageBuffer::canvas() const
 {
     if (!isSurfaceValid())
         return nullptr;
     return m_surface->canvas();
 }
 
-SkCanvas* ImageBuffer::immediateCanvas() const
+void ImageBuffer::disableDeferral() const
 {
-    if (!isSurfaceValid())
-        return nullptr;
-    return m_surface->immediateCanvas();
+    return m_surface->disableDeferral();
 }
 
 bool ImageBuffer::writePixels(const SkImageInfo& info, const void* pixels, size_t rowBytes, int x, int y)
 {
     return m_surface->writePixels(info, pixels, rowBytes, x, y);
 }
 
 const SkBitmap& ImageBuffer::deprecatedBitmapForOverwrite() const
 {
     return m_surface->deprecatedBitmapForOverwrite();
@@ skipping 253 matching lines @@
     ASSERT(MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType));
 
     Vector<char> encodedImage;
     if (!encodeImage(*this, mimeType, quality, &encodedImage))
         return "data:,";
 
     return "data:" + mimeType + ";base64," + base64Encode(encodedImage);
 }
 
 } // namespace blink