add ability to get FBO ID to Surface

src/image/SkSurface_Base.h

Index: src/image/SkSurface_Base.h
diff --git a/src/image/SkSurface_Base.h b/src/image/SkSurface_Base.h
index 3f1301ee34c1d7aa1afdfcf5a3cce0ffbda7a75b..b8eb7dd5f11d7ef92f927705d5ec27e8ff463d6f 100644
--- a/src/image/SkSurface_Base.h
+++ b/src/image/SkSurface_Base.h
@@ -18,10 +18,14 @@ public:
     SkSurface_Base(const SkImageInfo&, const SkSurfaceProps*);
     virtual ~SkSurface_Base();
 
-    virtual GrBackendObject onGetTextureHandle(TextureHandleAccess) {
+    virtual GrBackendObject onGetTextureHandle(BackendHandleAccess) {
         return 0;
     }
 
+    virtual bool onGetRenderTargetHandle(GrBackendObject*, BackendHandleAccess) {
+        return false;
+    }
+
     /**
      *  Allocate a canvas that will draw into this surface. We will cache this
      *  canvas, to return the same object to the caller multiple times. We