[Ozone] Fix build

ui/ozone/public/surface_ozone_canvas.h

 // Copyright 2014 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_OZONE_PUBLIC_SURFACE_OZONE_CANVAS_H_
 #define UI_OZONE_PUBLIC_SURFACE_OZONE_CANVAS_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "skia/ext/refptr.h"
 #include "ui/ozone/ozone_base_export.h"
 
-class SkCanvas;
+class SkSurface;
 
 namespace gfx {
 class Size;
 class VSyncProvider;
 }
 
 namespace ui {
 
 // The platform-specific part of an software output. The class is intended
 // for use when no EGL/GLES2 acceleration is possible.
 // This class owns any bits that the ozone implementation needs freed when
 // the software output is destroyed.
 class OZONE_BASE_EXPORT SurfaceOzoneCanvas {
  public:
   virtual ~SurfaceOzoneCanvas() {}
 
-  // Returns an SkCanvas for drawing on the window.
-  virtual skia::RefPtr<SkCanvas> GetCanvas() = 0;
+  // Returns an SkSurface for drawing on the window.
+  virtual skia::RefPtr<SkSurface> GetSurface() = 0;
 
   // Attempts to resize the canvas to match the viewport size. After
   // resizing, the compositor must call GetCanvas() to get the next
   // canvas - this invalidates any previous canvas from GetCanvas().
   virtual void ResizeCanvas(const gfx::Size& viewport_size) = 0;
 
   // Present the current canvas. After presenting, the compositor must
   // call GetCanvas() to get the next canvas - this invalidates any
   // previous canvas from GetCanvas().
   //
   // The implementation may assume that any pixels outside the damage
   // rectangle are unchanged since the previous call to PresentCanvas().
   virtual void PresentCanvas(const gfx::Rect& damage) = 0;
 
   // Returns a gfx::VsyncProvider for this surface. Note that this may be
   // called after we have entered the sandbox so if there are operations (e.g.
   // opening a file descriptor providing vsync events) that must be done
   // outside of the sandbox, they must have been completed in
   // InitializeHardware. Returns an empty scoped_ptr on error.
   virtual scoped_ptr<gfx::VSyncProvider> CreateVSyncProvider() = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PUBLIC_SURFACE_OZONE_CANVAS_H_