Implement support for expanding crop rects in image filters

src/effects/SkOffsetImageFilter.cpp

Index: src/effects/SkOffsetImageFilter.cpp
diff --git a/src/effects/SkOffsetImageFilter.cpp b/src/effects/SkOffsetImageFilter.cpp
index 98eb05bf1d3e44556d78032a58b1e99ca36f3cfb..ae35a4ca2f7875633cd3d40995ad97e328705e39 100644
--- a/src/effects/SkOffsetImageFilter.cpp
+++ b/src/effects/SkOffsetImageFilter.cpp
@@ -42,10 +42,7 @@ bool SkOffsetImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
         }
 
         SkIRect bounds;
-        src.getBounds(&bounds);
-        bounds.offset(srcOffset);
-
-        if (!applyCropRect(&bounds, ctx.ctm())) {
+        if (!this->applyCropRect(ctx, src, srcOffset, &bounds)) {
             return false;
         }