add SkImage::newSurface

src/image/SkImage.cpp

Index: src/image/SkImage.cpp
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index f11900dcaa29e7fa748d70f5c641280081bb383d..3f11aedeb7485425256a9f4095b2c09d8f48d5ea 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -9,6 +9,7 @@
 #include "SkCanvas.h"
 #include "SkImagePriv.h"
 #include "SkImage_Base.h"
+#include "SkSurface.h"
 
 static SkImage_Base* as_IB(SkImage* image) {
     return static_cast<SkImage_Base*>(image);
@@ -91,6 +92,10 @@ SkData* SkImage::encode(SkImageEncoder::Type type, int quality) const {
     return NULL;
 }
 
+SkSurface* SkImage::newSurface(const SkImageInfo& info, const SkSurfaceProps& props) const {
+    return as_IB(this)->onNewSurface(info, props);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static bool raster_canvas_supports(const SkImageInfo& info) {