Image filters: implement offsets in GPU path.

include/effects/SkBicubicImageFilter.h

 /*
  * Copyright 2013 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 SkBicubicImageFilter_DEFINED
 #define SkBicubicImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkScalar.h"
 #include "SkSize.h"
 #include "SkPoint.h"
 
 /*! \class SkBicubicImageFilter
     Bicubic resampling image filter.  This filter does a 16-tap bicubic
     filter using the given matrix.
  */
 
 class SK_API SkBicubicImageFilter : public SkImageFilter {
 public:
     /** Construct a (scaling-only) bicubic resampling image filter.
         @param scale        How much to scale the image.
         @param coefficients The 16 coefficients of the bicubic matrix.
         @param input        The input image filter.  If NULL, the src bitmap
                             passed to filterImage() is used instead.
     */
 
-    SkBicubicImageFilter(const SkSize& scale, const SkScalar coefficients[16], SkImageFilter* input = NULL);
+    SkBicubicImageFilter(const SkSize& scale, const SkScalar coefficients[16],
+                         SkImageFilter* input = NULL);
     static SkBicubicImageFilter* CreateMitchell(const SkSize& scale, SkImageFilter* input = NULL);
     virtual ~SkBicubicImageFilter();
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBicubicImageFilter)
 
 protected:
     SkBicubicImageFilter(SkFlattenableReadBuffer& buffer);
     virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* loc) SK_OVERRIDE;
 
 #if SK_SUPPORT_GPU
     virtual bool canFilterImageGPU() const SK_OVERRIDE { return true; }
-    virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result) SK_OVERRIDE;
+    virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result,
+                                SkIPoint* offset) SK_OVERRIDE;
 #endif
 
 private:
     SkSize    fScale;
     SkScalar  fCoefficients[16];
     typedef SkImageFilter INHERITED;
 };
 
 #endif