Add toString methods to SkImageFilter-derived classes

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, uint32_t uniqueID = 0);
 
     virtual bool onFilterImage(Proxy* proxy, const SkBitmap& src, const Context& ctx,
                                SkBitmap* dst, SkIPoint* offset) const SK_OVERRIDE;
     virtual bool onFilterBounds(const SkIRect& src, const SkMatrix&,
                                 SkIRect* dst) const SK_OVERRIDE;
 
+    SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTileImageFilter)
 
 protected:
     SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input, uint32_t uniqueID)
         : INHERITED(1, &input, NULL, uniqueID), fSrcRect(srcRect), fDstRect(dstRect) {}
 
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
 
 private:
     SkRect fSrcRect;
     SkRect fDstRect;
 };
 
 #endif