Image filters: remove SkBitmap-based cache.

include/effects/SkMatrixConvolutionImageFilter.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 SkMatrixConvolutionImageFilter_DEFINED
 #define SkMatrixConvolutionImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkScalar.h"
 #include "SkSize.h"
 #include "SkPoint.h"
 
+class SkBitmap;
+
 /*! \class SkMatrixConvolutionImageFilter
     Matrix convolution image filter.  This filter applies an NxM image
     processing kernel to a given input image.  This can be used to produce
     effects such as sharpening, blurring, edge detection, etc.
  */
 
 class SK_API SkMatrixConvolutionImageFilter : public SkImageFilter {
 public:
     /*! \enum TileMode */
     enum TileMode {
@@ skipping 96 matching lines @@
                               const SkIRect& bounds) const;
     void filterBorderPixels(const SkBitmap& src,
                             SkBitmap* result,
                             const SkIRect& rect,
                             const SkIRect& bounds) const;
 
     typedef SkImageFilter INHERITED;
 };
 
 #endif