Always enable register local implementaions into remote interfaces of rfh.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index fadeeca42041cb03120150ffe39978fa7c35804d..46ada0b1e700ce72a6ab69643d9a275db63bbc12 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -2394,6 +2394,11 @@ void RenderFrameHostImpl::SetUpMojoIfNeeded() {
     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;
 
@@ -2407,7 +2412,6 @@ void RenderFrameHostImpl::SetUpMojoIfNeeded() {
   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));