Add support for converting cc::FilterOperations into an SkImageFilter

cc/output/render_surface_filters.h

Index: cc/output/render_surface_filters.h
diff --git a/cc/output/render_surface_filters.h b/cc/output/render_surface_filters.h
index 5ab78dc77e7438ac31abcba184531e2ec98e0054..96aabb43235dbe4da731a5901449dc37756a7e66 100644
--- a/cc/output/render_surface_filters.h
+++ b/cc/output/render_surface_filters.h
@@ -8,9 +8,11 @@
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
+#include "skia/ext/refptr.h"
 
 class GrContext;
 class SkBitmap;
+class SkImageFilter;
 
 namespace gfx {
 class SizeF;
@@ -28,6 +30,9 @@ class CC_EXPORT RenderSurfaceFilters {
                         GrContext* gr_context);
   static FilterOperations Optimize(const FilterOperations& filters);
 
+  static skia::RefPtr<SkImageFilter> BuildImageFilter(
+      const FilterOperations& filters);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(RenderSurfaceFilters);
 };