Make filters use SkImage instead of SkBitmap

src/effects/SkRectShaderImageFilter.cpp

Index: src/effects/SkRectShaderImageFilter.cpp
diff --git a/src/effects/SkRectShaderImageFilter.cpp b/src/effects/SkRectShaderImageFilter.cpp
index a00994e75b64ffe5b5145822ac9a6c8db054a467..04060f102442523162de7e5074b86fd261fc1bd4 100644
--- a/src/effects/SkRectShaderImageFilter.cpp
+++ b/src/effects/SkRectShaderImageFilter.cpp
@@ -50,9 +50,9 @@ SkRectShaderImageFilter::~SkRectShaderImageFilter() {
 }
 
 bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
-                                            const SkBitmap& source,
+                                            const SkImage* source,
                                             const Context& ctx,
-                                            SkBitmap* result,
+                                            SkAutoTUnref<const SkImage>& result,
                                             SkIPoint* offset) const {
     SkIRect bounds;
     if (!this->applyCropRect(ctx, source, SkIPoint::Make(0, 0), &bounds)) {
@@ -73,8 +73,12 @@ bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
 
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
+    SkImage* image = device->newImageSnapshot();
+    if (NULL == image) {
+        return false;
+    }
+    result.reset(image);
 
-    *result = device.get()->accessBitmap(false);
     offset->fX = bounds.fLeft;
     offset->fY = bounds.fTop;
     return true;