Introduce PlatformBitmap, which is a minimal helper class that wraps an SkBitmap

content/browser/renderer_host/backing_store_aura.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/backing_store_aura.h"
 
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/public/browser/render_widget_host.h"
 #include "skia/ext/platform_canvas.h"
@@ skipping 128 matching lines @@
 
   int x = std::min(pixel_rect.x(), pixel_rect.x() - pixel_dx);
   int y = std::min(pixel_rect.y(), pixel_rect.y() - pixel_dy);
   int w = pixel_rect.width() + abs(pixel_dx);
   int h = pixel_rect.height() + abs(pixel_dy);
   SkIRect rect = SkIRect::MakeXYWH(x, y, w, h);
   bitmap_.scrollRect(&rect, pixel_dx, pixel_dy);
 }
 
 bool BackingStoreAura::CopyFromBackingStore(const gfx::Rect& rect,
-                                            skia::PlatformCanvas* output) {
+                                            skia::PlatformBitmap* output) {
   const int width =
       std::min(size().width(), rect.width()) * device_scale_factor_;
   const int height =
       std::min(size().height(), rect.height()) * device_scale_factor_;
-  if (!output->initialize(width, height, true))
+  if (!output->Allocate(width, height, true))
     return false;
 
-  SkBitmap bitmap = skia::GetTopDevice(*output)->accessBitmap(true);
   SkIRect skrect = SkIRect::MakeXYWH(rect.x(), rect.y(), width, height);
   SkBitmap b;
   if (!canvas_->readPixels(skrect, &b))
     return false;
-  output->writePixels(b, rect.x(), rect.y());
+  SkCanvas(output->GetBitmap()).writePixels(b, rect.x(), rect.y());
   return true;
 }
 
 }  // namespace content