blink: Cleanup class/struct forward declarations

third_party/WebKit/Source/platform/graphics/PlaceholderImage.h

 // Copyright 2016 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 PlaceholderImage_h
 #define PlaceholderImage_h
 
 #include "platform/SharedBuffer.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/Image.h"
 #include "platform/graphics/ImageOrientation.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "wtf/PassRefPtr.h"
 
 class SkCanvas;
 class SkPaint;
 
 namespace blink {
 
-class FloatPoint;
 class FloatRect;
-class FloatSize;
-class GraphicsContext;
 class ImageObserver;
 
 // A generated placeholder image that shows a translucent gray rectangle.
 class PLATFORM_EXPORT PlaceholderImage final : public Image {
  public:
   static PassRefPtr<PlaceholderImage> create(ImageObserver* observer,
                                              const IntSize& size) {
     return adoptRef(new PlaceholderImage(observer, size));
   }
 
@@ skipping 24 matching lines @@
   }
 
   IntSize m_size;
   // Lazily initialized.
   sk_sp<SkImage> m_imageForCurrentFrame;
 };
 
 }  // namespace blink
 
 #endif