add ability to get FBO ID to Surface

src/image/SkSurface_Gpu.h

Index: src/image/SkSurface_Gpu.h
diff --git a/src/image/SkSurface_Gpu.h b/src/image/SkSurface_Gpu.h
index ed94a24fcd0495713426190fb251f517e9c85ee2..23241540bfe3d95d7f550480204d230f77f14f06 100644
--- a/src/image/SkSurface_Gpu.h
+++ b/src/image/SkSurface_Gpu.h
@@ -16,12 +16,11 @@ class SkGpuDevice;
 
 class SkSurface_Gpu : public SkSurface_Base {
 public:
-    
-
     SkSurface_Gpu(SkGpuDevice*);
     virtual ~SkSurface_Gpu();
 
-    GrBackendObject onGetTextureHandle(TextureHandleAccess) override;
+    GrBackendObject onGetTextureHandle(BackendHandleAccess) override;
+    bool onGetRenderTargetHandle(GrBackendObject*, BackendHandleAccess) override;
     SkCanvas* onNewCanvas() override;
     SkSurface* onNewSurface(const SkImageInfo&) override;
     SkImage* onNewImageSnapshot(Budgeted) override;