Hide drawBatch on GrDrawTarget from test Methods

include/gpu/GrDrawContext.h

Index: include/gpu/GrDrawContext.h
diff --git a/include/gpu/GrDrawContext.h b/include/gpu/GrDrawContext.h
index 2f664ba443c83725a92e4190afc37059d6b79b64..47ede8b6c1cc1953186864328a18cfbab6cf3fcf 100644
--- a/include/gpu/GrDrawContext.h
+++ b/include/gpu/GrDrawContext.h
@@ -277,6 +277,10 @@ public:
 
     GrRenderTarget* accessRenderTarget() { return fRenderTarget; }
 
+    ///////////////////////////////////////////////////////////////////////////////////////////////
+    // Functions intended for internal use only.
+    void internal_drawBatch(GrPipelineBuilder* pipelineBuilder, GrDrawBatch* batch);
+
 private:
     friend class GrAtlasTextBlob; // for access to drawBatch
     friend class GrDrawingManager; // for ctor