Initial error handling code

include/core/SkImageFilter.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageFilter_DEFINED
 #define SkImageFilter_DEFINED
 
@@ skipping 122 matching lines @@
      *  Returns the crop rectangle of this filter. This is set at construction
      *  time, and determines which pixels from the input image will
      *  be processed. The size of this rectangle should be used as the size
      *  of the destination image. The origin of this rect should be used to
      *  offset access to the input images, and should also be added to the
      *  "offset" parameter in onFilterImage and filterImageGPU(). (The latter
      *  ensures that the resulting buffer is drawn in the correct location.)
      */
     const SkIRect& cropRect() const { return fCropRect; }
 
+    SK_DEFINE_FLATTENABLE_TYPE(SkImageFilter)
+
 protected:
     SkImageFilter(int inputCount, SkImageFilter** inputs, const SkIRect* cropRect = NULL);
 
     // Convenience constructor for 1-input filters.
     explicit SkImageFilter(SkImageFilter* input, const SkIRect* cropRect = NULL);
 
     // Convenience constructor for 2-input filters.
     SkImageFilter(SkImageFilter* input1, SkImageFilter* input2, const SkIRect* cropRect = NULL);
 
     virtual ~SkImageFilter();
@@ skipping 14 matching lines @@
     bool applyCropRect(SkIRect* rect, const SkMatrix& matrix) const;
 
 private:
     typedef SkFlattenable INHERITED;
     int fInputCount;
     SkImageFilter** fInputs;
     SkIRect fCropRect;
 };
 
 #endif