Move the "platform" wrappers in skia/ext to the skia namespace.

skia/ext/platform_canvas_mac.h

 // Copyright (c) 2006-2008 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 SKIA_EXT_PLATFORM_CANVAS_MAC_H_
 #define SKIA_EXT_PLATFORM_CANVAS_MAC_H_
 
 #include "skia/ext/platform_device_mac.h"
 
 #include "SkCanvas.h"
 
-namespace gfx {
+namespace skia {
 
 // This class is a specialization of the regular SkCanvas that is designed to
 // work with a gfx::PlatformDevice to manage platform-specific drawing. It
 // allows using both Skia operations and platform-specific operations.
 class PlatformCanvasMac : public SkCanvas {
  public:
   // Set is_opaque if you are going to erase the bitmap and not use
   // tranparency: this will enable some optimizations.  The shared_section
   // parameter is passed to gfx::PlatformDevice::create.  See it for details.
   //
@@ skipping 52 matching lines @@
   // Calling SkCanvas' version will create a new device which is not compatible
   // with us and we will crash if somebody tries to draw into it with
   // CoreGraphics.
   SkDevice* setBitmapDevice(const SkBitmap& bitmap);
 
   // Disallow copy and assign.
   PlatformCanvasMac(const PlatformCanvasMac&);
   PlatformCanvasMac& operator=(const PlatformCanvasMac&);
 };
 
-}  // namespace gfx
+}  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_MAC_H_