ui/gfx: Make gfx::Canvas inherit from gfx::CanvasSkia.

ui/gfx/compositor/layer_unittest.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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/canvas.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/compositor/compositor_observer.h"
 #include "ui/gfx/compositor/layer.h"
 #include "ui/gfx/compositor/layer_animation_sequence.h"
 #include "ui/gfx/compositor/test/test_compositor_host.h"
 #include "ui/gfx/gfx_paths.h"
 #include "ui/gfx/skia_util.h"
 
 #include "ui/gfx/compositor/compositor_setup.h"
 
@@ skipping 982 matching lines @@
   EXPECT_TRUE(schedule_draw_invoked_);
   // Because SchedulePaint() was invoked from OnPaintLayer() |child| should
   // still need to be painted.
   DrawTree(root.get());
   EXPECT_EQ(1, child_delegate.GetPaintCountAndClear());
   EXPECT_TRUE(child_delegate.last_clip_rect().Contains(
                   gfx::Rect(10, 10, 30, 30)));
 }
 
 } // namespace ui