Add support for converting cc::FilterOperations into an SkImageFilter

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index ba0ff7b8216a1aaa0dfe8d7c4915f01387470401..14560cc1264533657ce3971ec108665da5a0cfeb 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -193,9 +193,6 @@ class CC_EXPORT LayerImpl : LayerAnimationValueObserver {
     return background_filters_;
   }
 
-  void SetFilter(const skia::RefPtr<SkImageFilter>& filter);
-  skia::RefPtr<SkImageFilter> filter() const { return filter_; }
-
   void SetMasksToBounds(bool masks_to_bounds);
   bool masks_to_bounds() const { return masks_to_bounds_; }
 
@@ -597,7 +594,6 @@ class CC_EXPORT LayerImpl : LayerAnimationValueObserver {
 
   FilterOperations filters_;
   FilterOperations background_filters_;
-  skia::RefPtr<SkImageFilter> filter_;
 
  protected:
   DrawMode current_draw_mode_;