Use SkBitmap backing instead of GDI backed platform canvas for tiles

cc/resources/bitmap_content_layer_updater.cc

 // Copyright 2011 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 "cc/resources/bitmap_content_layer_updater.h"
 
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/resources/layer_painter.h"
 #include "cc/resources/prioritized_resource.h"
@@ skipping 48 matching lines @@
     float contents_width_scale,
     float contents_height_scale,
     gfx::Rect* resulting_opaque_rect) {
   devtools_instrumentation::ScopedLayerTask paint_layer(
       devtools_instrumentation::kPaintLayer, layer_id_);
   if (canvas_size_.width() < content_rect.size().width() ||
       canvas_size_.height() < content_rect.size().height()) {
     devtools_instrumentation::ScopedLayerTask paint_setup(
         devtools_instrumentation::kPaintSetup, layer_id_);
     canvas_size_ = content_rect.size();
-    canvas_ = skia::AdoptRef(skia::CreateBitmapCanvas(
-        canvas_size_.width(), canvas_size_.height(), layer_is_opaque_));
+    bitmap_backing_.setConfig(
+        SkBitmap::kARGB_8888_Config,
+        canvas_size_.width(), canvas_size_.height(),
+        0, layer_is_opaque_ ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
+    bitmap_backing_.allocPixels();
+    canvas_ = skia::AdoptRef(new SkCanvas(bitmap_backing_));
   }
 
   base::TimeTicks start_time =
       rendering_stats_instrumentation_->StartRecording();
   PaintContents(canvas_.get(),
                 content_rect,
                 contents_width_scale,
                 contents_height_scale,
                 resulting_opaque_rect);
   base::TimeDelta duration =
@@ skipping 27 matching lines @@
 void BitmapContentLayerUpdater::SetOpaque(bool opaque) {
   if (opaque != layer_is_opaque_) {
     canvas_.clear();
     canvas_size_ = gfx::Size();
   }
 
   ContentLayerUpdater::SetOpaque(opaque);
 }
 
 }  // namespace cc