Fix for SkDisplacementMap::onFilterBounds().

src/effects/SkDisplacementMapEffect.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 "SkDisplacementMapEffect.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
@@ skipping 239 matching lines @@
         getColorInput()->computeFastBounds(src, dst);
     } else {
         *dst = src;
     }
     dst->outset(fScale * SK_ScalarHalf, fScale * SK_ScalarHalf);
 }
 
 bool SkDisplacementMapEffect::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
                                    SkIRect* dst) const {
     SkIRect bounds = src;
-    if (getColorInput() && !getColorInput()->filterBounds(src, ctm, &bounds)) {
-        return false;
+    SkVector scale = SkVector::Make(fScale, fScale);
+    ctm.mapVectors(&scale, 1);
+    bounds.outset(SkScalarCeilToInt(scale.fX * SK_ScalarHalf),
+                  SkScalarCeilToInt(scale.fY * SK_ScalarHalf));
+    if (getColorInput()) {
+        return getColorInput()->filterBounds(bounds, ctm, dst);
     }
-    bounds.outset(SkScalarCeilToInt(fScale * SK_ScalarHalf),
-                  SkScalarCeilToInt(fScale * SK_ScalarHalf));
     *dst = bounds;
     return true;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
 class GrGLDisplacementMapEffect : public GrGLEffect {
 public:
     GrGLDisplacementMapEffect(const GrBackendEffectFactory& factory,
@@ skipping 329 matching lines @@
                                                         const GrGLCaps&) {
     const GrDisplacementMapEffect& displacementMap =
         drawEffect.castEffect<GrDisplacementMapEffect>();
 
     EffectKey xKey = displacementMap.xChannelSelector();
     EffectKey yKey = displacementMap.yChannelSelector() << kChannelSelectorKeyBits;
 
     return xKey | yKey;
 }
 #endif