Make filters use SkImage instead of SkBitmap

src/effects/SkMergeImageFilter.cpp

Index: src/effects/SkMergeImageFilter.cpp
diff --git a/src/effects/SkMergeImageFilter.cpp b/src/effects/SkMergeImageFilter.cpp
index 7034e158e5ef48e95d49007c180f09bee1443a05..5d7c752edab06186995ae1f3ccaf8d8a86ab209b 100755
--- a/src/effects/SkMergeImageFilter.cpp
+++ b/src/effects/SkMergeImageFilter.cpp
@@ -56,9 +56,10 @@ SkMergeImageFilter::~SkMergeImageFilter() {
     }
 }
 
-bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
+bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkImage* src,
                                        const Context& ctx,
-                                       SkBitmap* result, SkIPoint* offset) const {
+                                       SkAutoTUnref<const SkImage>& result,
+                                       SkIPoint* offset) const {
     if (countInputs() < 1) {
         return false;
     }
@@ -80,17 +81,11 @@ bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
 
     int inputCount = countInputs();
     for (int i = 0; i < inputCount; ++i) {
-        SkBitmap tmp;
-        const SkBitmap* srcPtr;
+        SkAutoTUnref<const SkImage> filteredImage(SkRef(src));
         SkIPoint pos = SkIPoint::Make(0, 0);
         SkImageFilter* filter = getInput(i);
-        if (filter) {
-            if (!filter->filterImage(proxy, src, ctx, &tmp, &pos)) {
-                return false;
-            }
-            srcPtr = &tmp;
-        } else {
-            srcPtr = &src;
+        if (filter && !filter->filterImage(proxy, src, ctx, filteredImage, &pos)) {
+            return false;
         }
 
         if (fModes) {
@@ -98,12 +93,15 @@ bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
         } else {
             paint.setXfermode(NULL);
         }
-        canvas.drawSprite(*srcPtr, pos.x() - x0, pos.y() - y0, &paint);
+        canvas.drawSprite(*filteredImage, pos.x() - x0, pos.y() - y0, &paint);
     }
-
+    SkImage* image = dst->newImageSnapshot();
+    if (NULL == image) {
+        return false;
+    }
+    result.reset(image);
     offset->fX = bounds.left();
     offset->fY = bounds.top();
-    *result = dst->accessBitmap(false);
     return true;
 }