Implement support for a Context parameter in image filters

include/effects/SkTileImageFilter.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTileImageFilter_DEFINED
 #define SkTileImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 
 class SK_API SkTileImageFilter : public SkImageFilter {
     typedef SkImageFilter INHERITED;
 
 public:
     /** Create a tile image filter
         @param srcRect  Defines the pixels to tile
         @param dstRect  Defines the pixels where tiles are drawn
         @param input    Input from which the subregion defined by srcRect will be tiled
     */
     static SkTileImageFilter* Create(const SkRect& srcRect, const SkRect& dstRect,
                                      SkImageFilter* input) {
         return SkNEW_ARGS(SkTileImageFilter, (srcRect, dstRect, input));
     }
 
-    virtual bool onFilterImage(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
+    virtual bool onFilterImage(Proxy* proxy, const SkBitmap& src, const Context& ctx,
                                SkBitmap* dst, SkIPoint* offset) const SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTileImageFilter)
 
 protected:
     explicit SkTileImageFilter(SkReadBuffer& buffer);
 
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
 
 #ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
 public:
 #endif
     SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input)
         : INHERITED(input), fSrcRect(srcRect), fDstRect(dstRect) {}
 
 private:
     SkRect fSrcRect;
     SkRect fDstRect;
 };
 
 #endif