[Autofill] Migrate ContentAutofillDriver<-->AutofillAgent IPCs to mojo.

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

[Ken Rockot(use gerrit already), 2016/06/29 22:33:21]

nit: "The RenderProcessHost may not have remote interfaces in some test
environments. In that case we create an empty InterfaceProvider so tests can
register mock implementations."

[leonhsl(Using Gerrit), 2016/07/01 13:04:59]

Done.

+  // MockRenderProcessHost, here still create |remote_interfaces_| to enable
+  // test codes register local implementations.
+  remote_interfaces_.reset(new shell::InterfaceProvider);

[Ken Rockot(use gerrit already), 2016/06/29 22:33:21]

nit: Move this into the if condition just below

[leonhsl(Using Gerrit), 2016/07/01 13:04:59]

Done.

   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));