Implement correct clipping for image filters.

src/effects/SkMergeImageFilter.cpp

 /*
  * 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.
  */
 
 #include "SkMergeImageFilter.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
@@ skipping 47 matching lines @@
     this->initModes(modes);
 }
 
 SkMergeImageFilter::~SkMergeImageFilter() {
 
     if (fModes != SkTCast<uint8_t*>(fStorage)) {
         sk_free(fModes);
     }
 }
 
-bool SkMergeImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
-                                        SkIRect* dst) {
-    if (countInputs() < 1) {
-        return false;
-    }
-
-    SkIRect totalBounds;
-
-    int inputCount = countInputs();
-    for (int i = 0; i < inputCount; ++i) {
-        SkImageFilter* filter = getInput(i);
-        SkIRect r;
-        if (filter) {
-            if (!filter->filterBounds(src, ctm, &r)) {
-                return false;
-            }
-        } else {
-            r = src;
-        }
-        if (0 == i) {
-            totalBounds = r;
-        } else {
-            totalBounds.join(r);
-        }
-    }
-
-    // don't modify dst until now, so we don't accidentally change it in the
-    // loop, but then return false on the next filter.
-    *dst = totalBounds;
-    return true;
-}
-
 bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                        const SkMatrix& ctm,
                                        SkBitmap* result, SkIPoint* offset) {
     if (countInputs() < 1) {
         return false;
     }
 
     SkIRect bounds;
     src.getBounds(&bounds);
     if (!this->applyCropRect(&bounds, ctm)) {
@@ skipping 59 matching lines @@
         if (buffer.validate(buffer.getArrayCount() == size) &&
             buffer.readByteArray(fModes, size)) {
             for (int i = 0; i < nbInputs; ++i) {
                 buffer.validate(SkIsValidMode((SkXfermode::Mode)fModes[i]));
             }
         }
     } else {
         fModes = 0;
     }
 }