Trim Skia dependencies in Blink

third_party/WebKit/Source/platform/graphics/PaintGeneratedImage.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 PaintGeneratedImage_h
 #define PaintGeneratedImage_h
 
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/GeneratedImage.h"
 #include "wtf/OwnPtr.h"
 
+class SkPicture;
+
 namespace blink {
 
 class PLATFORM_EXPORT PaintGeneratedImage : public GeneratedImage {
 public:
     static PassRefPtr<PaintGeneratedImage> create(PassRefPtr<SkPicture> picture, const IntSize& size)
     {
         return adoptRef(new PaintGeneratedImage(picture, size));
     }
     ~PaintGeneratedImage() override { }
 
 protected:
     void draw(SkCanvas*, const SkPaint&, const FloatRect&, const FloatRect&, RespectImageOrientationEnum, ImageClampingMode) override;
     void drawTile(GraphicsContext&, const FloatRect&) final;
 
     PaintGeneratedImage(PassRefPtr<SkPicture> picture, const IntSize& size)
         : GeneratedImage(size)
         , m_picture(picture)
     {
     }
 
     RefPtr<SkPicture> m_picture;
 };
 
 } // namespace blink
 
 #endif // PaintGeneratedImage_h