Make filters use SkImage instead of SkBitmap

include/effects/SkXfermodeImageFilter.h

Index: include/effects/SkXfermodeImageFilter.h
diff --git a/include/effects/SkXfermodeImageFilter.h b/include/effects/SkXfermodeImageFilter.h
index 66df053ba71d03b78ffb88c705c862c9853ef1f3..6388ba105c35d4d48c5f74e8dc4f497123e768d6 100644
--- a/include/effects/SkXfermodeImageFilter.h
+++ b/include/effects/SkXfermodeImageFilter.h
@@ -10,7 +10,6 @@
 
 #include "SkImageFilter.h"
 
-class SkBitmap;
 class SkXfermode;
 
 class SK_API SkXfermodeImageFilter : public SkImageFilter {
@@ -34,14 +33,14 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkXfermodeImageFilter)
 
     virtual bool onFilterImage(Proxy* proxy,
-                               const SkBitmap& src,
+                               const SkImage* src,
                                const Context& ctx,
-                               SkBitmap* dst,
+                               SkAutoTUnref<const SkImage>& dst,
                                SkIPoint* offset) const SK_OVERRIDE;
 #if SK_SUPPORT_GPU
     bool canFilterImageGPU() const SK_OVERRIDE;
-    virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const Context& ctx,
-                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
+    virtual bool filterImageGPU(Proxy* proxy, const SkImage* src, const Context& ctx,
+                                SkAutoTUnref<const SkImage>& result, SkIPoint* offset) const SK_OVERRIDE;
 #endif
 
 protected: