Always enable register local implementaions into remote interfaces of rfh.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 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.
 
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 2376 matching lines @@
   // An error page is expected to commit, hence why is_loading_ is set to true.
   is_loading_ = true;
   frame_tree_node_->ResetNavigationRequest(true);
 }
 
 void RenderFrameHostImpl::SetUpMojoIfNeeded() {
   if (interface_registry_.get())
     return;
 
   interface_registry_.reset(new shell::InterfaceRegistry(nullptr));
+
+  // Even RenderProcessHost has no remote interfaces, such as
+  // MockRenderProcessHost, here still create |remote_interfaces_| to enable
+  // test codes register local implementations.
+  remote_interfaces_.reset(new shell::InterfaceProvider);

[Ben Goodger (Google), 2016/06/29 17:55:54]

Is this blocking something you want to do? I don't see code in this CL that
relies on this behavior.

(context: I'm working towards making it be the case that the check on the
following line is unnecessary)

[leonhsl(Using Gerrit), 2016/06/29 22:25:33]

In my another CL 
https://codereview.chromium.org/2007473004/diff/140001/components/autofill/co...
line#268, the remote_interfaces of main RFH is found to be nullptr.
And, also in that CL
https://codereview.chromium.org/2007473004/diff/140001/components/autofill/co...
because line#261 is trying to access RFH's InterfaceProvider, some test codes
maybe trigger this line execute ended with a nullptr access. Although we can add
some guard codes to avoid the nullptr access there.

I think this would be a general issue so I created this CL separately and want
to land it firstly.

   if (!GetProcess()->GetRemoteInterfaces())
     return;
 
   RegisterMojoInterfaces();
   mojom::FrameFactoryPtr frame_factory;
   GetProcess()->GetRemoteInterfaces()->GetInterface(&frame_factory);
   frame_factory->CreateFrame(routing_id_, GetProxy(&frame_),
                              frame_host_binding_.CreateInterfacePtrAndBind());
 
 
   shell::mojom::InterfaceProviderPtr remote_interfaces;
   shell::mojom::InterfaceProviderRequest remote_interfaces_request =
       GetProxy(&remote_interfaces);
-  remote_interfaces_.reset(new shell::InterfaceProvider);
   remote_interfaces_->Bind(std::move(remote_interfaces));
   frame_->GetInterfaceProvider(std::move(remote_interfaces_request));
 
 #if defined(OS_ANDROID)
   service_registry_android_ =
       ServiceRegistryAndroid::Create(interface_registry_.get(),
                                      remote_interfaces_.get());
   ServiceRegistrarAndroid::RegisterFrameHostServices(
       service_registry_android_.get());
 #endif
@@ skipping 537 matching lines @@
   // handler after it's destroyed so it can't run after the RFHI is destroyed.
   web_bluetooth_service_->SetClientConnectionErrorHandler(base::Bind(
       &RenderFrameHostImpl::DeleteWebBluetoothService, base::Unretained(this)));
 }
 
 void RenderFrameHostImpl::DeleteWebBluetoothService() {
   web_bluetooth_service_.reset();
 }
 
 }  // namespace content