Switch SkImageSource image filter over to new onFilterImage interface

include/effects/SkImageSource.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageSource_DEFINED
 #define SkImageSource_DEFINED
 
@@ skipping 10 matching lines @@
                                  SkFilterQuality);
 
     void computeFastBounds(const SkRect& src, SkRect* dst) const override;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkImageSource)
 
 protected:
     void flatten(SkWriteBuffer&) const override;
 
-    bool onFilterImageDeprecated(Proxy*, const SkBitmap& src, const Context&,
-                                 SkBitmap* result, SkIPoint* offset) const override;
+    SkSpecialImage* onFilterImage(SkSpecialImage* source, const Context&,
+                                  SkIPoint* offset) const override;
 
 private:
     explicit SkImageSource(const SkImage*);
     SkImageSource(const SkImage*,
                   const SkRect& srcRect,
                   const SkRect& dstRect,
                   SkFilterQuality);
 
     SkAutoTUnref<const SkImage> fImage;
     SkRect                      fSrcRect, fDstRect;
     SkFilterQuality             fFilterQuality;
 
     typedef SkImageFilter INHERITED;
 };
 
 #endif