Clean-up: Removes an unused forward declaration in canvas.h.

ui/gfx/canvas.h

 // Copyright (c) 2012 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_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "skia/ext/platform_canvas.h"
 #include "skia/ext/refptr.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/shadow_value.h"
 
 namespace gfx {
 
 class Rect;
-class Font;
 class FontList;
 class Point;
 class Size;
 class Transform;
 
 // Canvas is a SkCanvas wrapper that provides a number of methods for
 // common operations used throughout an application built using ui/gfx.
 //
 // All methods that take integer arguments (as is used throughout views)
 // end with Int. If you need to use methods provided by SkCanvas, you'll
@@ skipping 412 matching lines @@
 
   skia::RefPtr<skia::PlatformCanvas> owned_canvas_;
   SkCanvas* canvas_;
 
   DISALLOW_COPY_AND_ASSIGN(Canvas);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CANVAS_H_