Refactor the PlatformContext layer to have only one class.

app/gfx/canvas_paint.h

Index: app/gfx/canvas_paint.h
diff --git a/app/gfx/canvas_paint.h b/app/gfx/canvas_paint.h
new file mode 100755
index 0000000000000000000000000000000000000000..0b3c2a7780e5dfb65a3c9bf7104099414b0dcbef
--- /dev/null
+++ b/app/gfx/canvas_paint.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2009 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.
+
+#ifndef APP_GFX_CANVAS_PAINT_H_
+#define APP_GFX_CANVAS_PAINT_H_
+
+#include "app/gfx/canvas.h"
+#include "skia/ext/canvas_paint.h"
+
+// Define a skia::CanvasPaint type that wraps our gfx::Canvas like the
+// skia::PlatformCanvasPaint wraps PlatformCanvas.
+
+namespace gfx {
+
+#if defined(OS_WIN) || defined(OS_LINUX)
+typedef skia::CanvasPaintT<Canvas> CanvasPaint;
+#endif
+
+}  // namespace gfx
+
+#endif  // APP_GFX_CANVAS_PAINT_H_