Matrix convolution bounds fix; affectsTransparentBlack fixes.

src/effects/SkRectShaderImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRectShaderImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 61 matching lines @@
 
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
 
     *result = device.get()->accessBitmap(false);
     offset->fX = bounds.fLeft;
     offset->fY = bounds.fTop;
     return true;
 }
 
-bool SkRectShaderImageFilter::affectsTransparentBlack() const {
-    return true;
+bool SkRectShaderImageFilter::canComputeFastBounds() const {
+    // http:skbug.com/4627: "make computeFastBounds and onFilterBounds() CropRect-aware"
+    // computeFastBounds() doesn't currently take the crop rect into account,
+    // so we can't compute it. If a full crop rect is set, we should return true here.
+    return false;
 }
 
 #ifndef SK_IGNORE_TO_STRING
 void SkRectShaderImageFilter::toString(SkString* str) const {
     str->appendf("SkRectShaderImageFilter: (");
     str->append(")");
 }
 #endif