PROTOTYPE: PlzNavigate: use a Mojo data pipe to stream navigation data to the renderer.

content/common/render_frame_setup.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module content;
 
 import "mojo/shell/public/interfaces/service_provider.mojom";
 
 interface RenderFrameSetup {
   ExchangeServiceProviders(int32 frame_routing_id,
                            mojo.ServiceProvider& services,
                            mojo.ServiceProvider exposed_services);
 };
+
+
+// MOVE THIS SOMEWHERE ELSE? NEW FILE?
+interface DataPipeConsumerHandleReceiver {
+  ReceiveDataPipeConsumerHandle(handle<data_pipe_consumer> data_consumer_handle, int32 handle_commit_id);
+};