Revert of Revert of 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 c401a905ff2177ca2ffd523c28f78639d8cc2ef7..15e44ab593675acc7f03db4dd214b867c9ec0153 100644
--- a/include/gpu/GrSurface.h
+++ b/include/gpu/GrSurface.h
@@ -15,6 +15,7 @@
 
 class GrTexture;
 class GrRenderTarget;
+struct SkImageInfo;
 
 class GrSurface : public GrResource {
 public:
@@ -57,6 +58,8 @@
      * Return the descriptor describing the surface
      */
     const GrTextureDesc& desc() const { return fDesc; }
+
+    void asImageInfo(SkImageInfo*) const;
 
     /**
      * @return the texture associated with the surface, may be NULL.