Move code to dump GrSurface as a png to helper files

src/gpu/GrSurfacePriv.h

Index: src/gpu/GrSurfacePriv.h
diff --git a/src/gpu/GrSurfacePriv.h b/src/gpu/GrSurfacePriv.h
index 3203671fadc4b806a6f9b639f87b46354152519a..54bf033d28f41fbc82d26db5eeb212d366f3316a 100644
--- a/src/gpu/GrSurfacePriv.h
+++ b/src/gpu/GrSurfacePriv.h
@@ -9,6 +9,7 @@
 #define GrSurfacePriv_DEFINED
 
 #include "GrSurface.h"
+#include "SkImagesSupport.h"
 
 /** Class that adds methods to GrSurface that are only intended for use internal to Skia.
     This class is purely a privileged window into GrSurface. It should never have additional data
@@ -30,12 +31,6 @@ public:
      */
     bool isSameAs(const GrSurface* other) const { return fSurface->isSameAs(other); }
 
-    /**
-     * Write the contents of the surface to a PNG. Returns true if successful.
-     * @param filename      Full path to desired file
-     */
-    bool savePixels(const char* filename) { return fSurface->savePixels(filename); }
-
     bool hasPendingRead() const { return fSurface->hasPendingRead(); }
     bool hasPendingWrite() const { return fSurface->hasPendingWrite(); }
     bool hasPendingIO() const { return fSurface->hasPendingIO(); }