Use SkMatrix44 for the underlying implementation of ui::Transform

ui/gfx/canvas.h

 // Copyright (c) 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.
 
 #ifndef UI_GFX_CANVAS_H_
 #define UI_GFX_CANVAS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 196 matching lines @@
                             int dest_x, int dest_y, int w, int h) = 0;
 
   // Returns a native drawing context for platform specific drawing routines to
   // use. Must be balanced by a call to EndPlatformPaint().
   virtual gfx::NativeDrawingContext BeginPlatformPaint() = 0;
 
   // Signifies the end of platform drawing using the native drawing context
   // returned by BeginPlatformPaint().
   virtual void EndPlatformPaint() = 0;
 
+#if !defined(OS_MACOSX)

[tomhudson, 2011/07/06 14:18:15]

OK, after so much work has been done it feels like I'm coming late to the party,
but - why #ifdef out this one function on Mac? We know Skia-as-Mac-backend isn't
widely distributed yet (although it's in the codebase as a compile flag now and
we hope to ship it c. M15), but is there some reason the rest of the class
compiles and this one function doesn't? It seems like clients would have to
contort their use of this class in a way that they're going to have to rip out
when Skia is the Mac backend.

   // Apply transformation on the canvas.
   virtual void Transform(const ui::Transform& transform) = 0;
+#endif
 
   // Create a texture ID that can be used for accelerated drawing.
   virtual ui::TextureID GetTextureID() = 0;
 
   // TODO(beng): remove this once we don't need to use any skia-specific methods
   //             through this interface.
   // A quick and dirty way to obtain the underlying SkCanvas.
   virtual CanvasSkia* AsCanvasSkia();
   virtual const CanvasSkia* AsCanvasSkia() const;
 };
@@ skipping 12 matching lines @@
   // Returns the rectangle that is invalid.
   virtual gfx::Rect GetInvalidRect() const = 0;
 
   // Returns the underlying Canvas.
   virtual Canvas* AsCanvas() = 0;
 };
 
 }  // namespace gfx;
 
 #endif  // UI_GFX_CANVAS_H_