Miscellaneous cleanup to reduce number of includes in platform/graphics/

Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 19 matching lines @@
 
 #include "core/html/HTMLElement.h"
 #include "core/platform/graphics/FloatRect.h"
 #include "core/platform/graphics/IntSize.h"
 #include <wtf/Forward.h>
 
 #define DefaultInterpolationQuality InterpolationMedium
 
 namespace WebCore {
 
+class AffineTransform;
 class CanvasContextAttributes;
 class CanvasRenderingContext;
 class GraphicsContext;
 class GraphicsContextStateSaver;
 class HTMLCanvasElement;
 class Image;
 class ImageData;
 class ImageBuffer;
 class IntSize;
 
@@ skipping 125 matching lines @@
     mutable OwnPtr<ImageBuffer> m_imageBuffer;
     mutable OwnPtr<GraphicsContextStateSaver> m_contextStateSaver;
     
     mutable RefPtr<Image> m_presentedImage;
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 } //namespace
 
 #endif