Make SkImageFilter methods const.

include/effects/SkMorphologyImageFilter.h

 /*
  * Copyright 2012 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 SkMorphologyImageFilter_DEFINED
 #define SkMorphologyImageFilter_DEFINED
@@ skipping 14 matching lines @@
      * of the destination buffer (in pixels), and srcStride and dstStride are the
      * number of pixels per row in each buffer. All buffers are 8888.
      */
 
     typedef void (*Proc)(const SkPMColor* src, SkPMColor* dst, int radius,
                          int width, int height, int srcStride, int dstStride);
 
 protected:
     bool filterImageGeneric(Proc procX, Proc procY,
                             Proxy*, const SkBitmap& src, const SkMatrix&,
-                            SkBitmap* result, SkIPoint* offset);
+                            SkBitmap* result, SkIPoint* offset) const;
     SkMorphologyImageFilter(SkReadBuffer& buffer);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 #if SK_SUPPORT_GPU
     virtual bool canFilterImageGPU() const SK_OVERRIDE { return true; }
     bool filterImageGPUGeneric(bool dilate, Proxy* proxy, const SkBitmap& src,
                                const SkMatrix& ctm, SkBitmap* result,
-                               SkIPoint* offset);
+                               SkIPoint* offset) const;
 #endif
 
     SkISize    radius() const { return fRadius; }
 
 private:
     SkISize    fRadius;
     typedef SkImageFilter INHERITED;
 };
 
 class SK_API SkDilateImageFilter : public SkMorphologyImageFilter {
 public:
     SkDilateImageFilter(int radiusX, int radiusY,
                         SkImageFilter* input = NULL,
                         const CropRect* cropRect = NULL)
     : INHERITED(radiusX, radiusY, input, cropRect) {}
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
-                               SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
+                               SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #if SK_SUPPORT_GPU
     virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
-                                SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
+                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #endif
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDilateImageFilter)
 
 protected:
     SkDilateImageFilter(SkReadBuffer& buffer) : INHERITED(buffer) {}
 
 private:
     typedef SkMorphologyImageFilter INHERITED;
 };
 
 class SK_API SkErodeImageFilter : public SkMorphologyImageFilter {
 public:
     SkErodeImageFilter(int radiusX, int radiusY,
                        SkImageFilter* input = NULL,
                        const CropRect* cropRect = NULL)
     : INHERITED(radiusX, radiusY, input, cropRect) {}
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
-                               SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
+                               SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #if SK_SUPPORT_GPU
     virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
-                                SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
+                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #endif
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkErodeImageFilter)
 
 protected:
     SkErodeImageFilter(SkReadBuffer& buffer) : INHERITED(buffer) {}
 
 private:
     typedef SkMorphologyImageFilter INHERITED;
 };
 
 #endif