Image filters: de-nest SkImageFilter::Cache and Cache::Key.

include/core/SkDevice.h

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDevice_DEFINED
 #define SkDevice_DEFINED
 
 #include "SkRefCnt.h"
 #include "SkCanvas.h"
 #include "SkColor.h"
-#include "SkImageFilter.h"
 #include "SkSurfaceProps.h"
 
 class SkBitmap;
 class SkClipStack;
 class SkDraw;
 class SkDrawFilter;
+class SkImageFilterCache;
 struct SkIRect;
 class SkMatrix;
 class SkMetaData;
 class SkRegion;
 class GrRenderTarget;
 
 class SK_API SkBaseDevice : public SkRefCnt {
 public:
     /**
      *  Construct a new device.
@@ skipping 356 matching lines @@
 
     virtual bool forceConservativeRasterClip() const { return false; }
 
     // just called by SkCanvas when built as a layer
     void setOrigin(int x, int y) { fOrigin.set(x, y); }
 
     /** Causes any deferred drawing to the device to be completed.
      */
     virtual void flush() {}
 
-    virtual SkImageFilter::Cache* getImageFilterCache() { return NULL; }
+    virtual SkImageFilterCache* getImageFilterCache() { return NULL; }
 
     SkIPoint    fOrigin;
     SkMetaData* fMetaData;
     SkSurfaceProps fSurfaceProps;
 
 #ifdef SK_DEBUG
     bool        fAttachedToCanvas;
 #endif
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif