Reland of Implement canComputeFastBounds() for image filters.

gm/imagefiltersscaled.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "sk_tool_utils.h"
 #include "SkBitmapSource.h"
 #include "SkBlurImageFilter.h"
@@ skipping 113 matching lines @@
 
         for (size_t j = 0; j < SK_ARRAY_COUNT(scales); ++j) {
             canvas->save();
             for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
                 SkPaint paint;
                 paint.setColor(SK_ColorBLUE);
                 paint.setImageFilter(filters[i]);
                 paint.setAntiAlias(true);
                 canvas->save();
                 canvas->scale(scales[j].fX, scales[j].fY);
+                canvas->clipRect(r);
                 if (5 == i) {
                     canvas->translate(SkIntToScalar(-32), 0);
                 } else if (6 == i) {
                     canvas->scale(SkScalarInvert(RESIZE_FACTOR),
                                   SkScalarInvert(RESIZE_FACTOR));
                 }
                 canvas->drawCircle(r.centerX(), r.centerY(), r.width()*2/5, paint);
                 canvas->restore();
                 canvas->translate(r.width() * scales[j].fX + margin, 0);
             }
@@ skipping 12 matching lines @@
     SkBitmap fGradientCircle;
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new ImageFiltersScaledGM; }
 static GMRegistry reg(MyFactory);
 
 }