Revert "remvoe duplicate impl for SkImageInfo flattening"

include/gpu/GrSurface.h

Index: include/gpu/GrSurface.h
diff --git a/include/gpu/GrSurface.h b/include/gpu/GrSurface.h
index 15e44ab593675acc7f03db4dd214b867c9ec0153..c401a905ff2177ca2ffd523c28f78639d8cc2ef7 100644
--- a/include/gpu/GrSurface.h
+++ b/include/gpu/GrSurface.h
@@ -15,7 +15,6 @@
 
 class GrTexture;
 class GrRenderTarget;
-struct SkImageInfo;
 
 class GrSurface : public GrResource {
 public:
@@ -59,8 +58,6 @@ public:
      */
     const GrTextureDesc& desc() const { return fDesc; }
 
-    void asImageInfo(SkImageInfo*) const;
-
     /**
      * @return the texture associated with the surface, may be NULL.
      */