Start using RenderTargetProxy (omnibus)

src/image/SkSurface_Gpu.cpp

Index: src/image/SkSurface_Gpu.cpp
diff --git a/src/image/SkSurface_Gpu.cpp b/src/image/SkSurface_Gpu.cpp
index 13bbd4f2e879622b3b2bdbc9519fef10cc47bd06..8cb25e90e2a87f4ad6cb02942dac1091aa7d86fa 100644
--- a/src/image/SkSurface_Gpu.cpp
+++ b/src/image/SkSurface_Gpu.cpp
@@ -41,7 +41,7 @@ static GrRenderTarget* prepare_rt_for_external_access(SkSurface_Gpu* surface,
     // Grab the render target *after* firing notifications, as it may get switched if CoW kicks in.
     surface->getDevice()->flush();
     GrRenderTargetContext* rtc = surface->getDevice()->accessRenderTargetContext();
-    return rtc->accessRenderTarget();
+    return rtc->instantiate();
 }
 
 GrBackendObject SkSurface_Gpu::onGetTextureHandle(BackendHandleAccess access) {