cc: Increment the ref count when assigning the SkImageFilter

cc/damage_tracker.h

Index: cc/damage_tracker.h
diff --git a/cc/damage_tracker.h b/cc/damage_tracker.h
index 190c92adbc8e70839dbf0882cfff7b4bf7a2e747..3b7ba1408b193036c75f56374385242a2c236425 100644
--- a/cc/damage_tracker.h
+++ b/cc/damage_tracker.h
@@ -8,11 +8,11 @@
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/cc_export.h"
+#include "third_party/skia/include/core/SkImageFilter.h"
+#include "third_party/skia/include/core/SkRefCnt.h"
 #include "ui/gfx/rect_f.h"
 #include <vector>
 
-class SkImageFilter;
-
 namespace gfx {
 class Rect;
 }
@@ -35,7 +35,7 @@ public:
 
     void didDrawDamagedArea() { m_currentDamageRect = gfx::RectF(); }
     void forceFullDamageNextUpdate() { m_forceFullDamageNextUpdate = true; }
-    void updateDamageTrackingState(const std::vector<LayerImpl*>& layerList, int targetSurfaceLayerID, bool targetSurfacePropertyChangedOnlyFromDescendant, const gfx::Rect& targetSurfaceContentRect, LayerImpl* targetSurfaceMaskLayer, const WebKit::WebFilterOperations&, SkImageFilter* filter);
+    void updateDamageTrackingState(const std::vector<LayerImpl*>& layerList, int targetSurfaceLayerID, bool targetSurfacePropertyChangedOnlyFromDescendant, const gfx::Rect& targetSurfaceContentRect, LayerImpl* targetSurfaceMaskLayer, const WebKit::WebFilterOperations&, const SkRefPtr<SkImageFilter>& filter);
 
     const gfx::RectF& currentDamageRect() { return m_currentDamageRect; }