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

skia/ext/platform_canvas_win.h

Index: skia/ext/platform_canvas_win.h
===================================================================
--- skia/ext/platform_canvas_win.h	(revision 6968)
+++ skia/ext/platform_canvas_win.h	(working copy)
@@ -12,11 +12,11 @@
 
 #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.
+// work with a PlatformDevice to manage platform-specific drawing. It allows
+// using both Skia operations and platform-specific operations.
 class PlatformCanvasWin : public SkCanvas {
  public:
   // Set is_opaque if you are going to erase the bitmap and not use
@@ -196,7 +196,7 @@
 
 typedef CanvasPaintT<PlatformCanvasWin> PlatformCanvasWinPaint;
 
-}  // namespace gfx
+}  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_WIN_H_