Optimize CSS box-shadow performance

src/core/SkMaskFilter.cpp

Index: src/core/SkMaskFilter.cpp
diff --git a/src/core/SkMaskFilter.cpp b/src/core/SkMaskFilter.cpp
index 86f303c56126fa6da892d0725d7cad1260dbdd7b..91c012ec640cc736c1b9e0d22636142285b02783 100644
--- a/src/core/SkMaskFilter.cpp
+++ b/src/core/SkMaskFilter.cpp
@@ -21,7 +21,7 @@
 #endif
 
 bool SkMaskFilter::filterMask(SkMask*, const SkMask&, const SkMatrix&,
-                              SkIPoint*) const {
+                              SkIPoint*, SkCachedData**) const {
     return false;
 }
 
@@ -219,7 +219,7 @@ bool SkMaskFilter::filterRRect(const SkRRect& devRRect, const SkMatrix& matrix,
         return false;
     }
     draw_nine(patch.fMask, patch.fOuterRect, patch.fCenter, true, clip, blitter);
-    SkMask::FreeImage(patch.fMask.fImage);
+    patch.fData->unref();
     return true;
 }
 
@@ -244,7 +244,7 @@ bool SkMaskFilter::filterPath(const SkPath& devPath, const SkMatrix& matrix,
             case kTrue_FilterReturn:
                 draw_nine(patch.fMask, patch.fOuterRect, patch.fCenter, 1 == rectCount, clip,
                           blitter);
-                SkMask::FreeImage(patch.fMask.fImage);
+                patch.fData->unref();
                 return true;
 
             case kUnimplemented_FilterReturn:
@@ -263,7 +263,7 @@ bool SkMaskFilter::filterPath(const SkPath& devPath, const SkMatrix& matrix,
     }
     SkAutoMaskFreeImage autoSrc(srcM.fImage);
 
-    if (!this->filterMask(&dstM, srcM, matrix, NULL)) {
+    if (!this->filterMask(&dstM, srcM, matrix, NULL, NULL)) {
         return false;
     }
     SkAutoMaskFreeImage autoDst(dstM.fImage);
@@ -342,7 +342,7 @@ void SkMaskFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
     srcM.fFormat = SkMask::kA8_Format;
 
     SkIPoint margin;    // ignored
-    if (this->filterMask(&dstM, srcM, SkMatrix::I(), &margin)) {
+    if (this->filterMask(&dstM, srcM, SkMatrix::I(), &margin, NULL)) {
         dst->set(dstM.fBounds);
     } else {
         dst->set(srcM.fBounds);