Set up Mojo connection when RenderFrameHost is reused for new RenderFrame

content/browser/frame_host/render_frame_host_manager.cc

Index: content/browser/frame_host/render_frame_host_manager.cc
diff --git a/content/browser/frame_host/render_frame_host_manager.cc b/content/browser/frame_host/render_frame_host_manager.cc
index 39799b9c099cbc9297567e14ea61886f554c1ae8..168cb421180808aab76decfecfbd092ebc384a51 100644
--- a/content/browser/frame_host/render_frame_host_manager.cc
+++ b/content/browser/frame_host/render_frame_host_manager.cc
@@ -186,6 +186,10 @@ RenderFrameHostImpl* RenderFrameHostManager::Navigate(
   // If the renderer crashed, then try to create a new one to satisfy this
   // navigation request.
   if (!dest_render_frame_host->IsRenderFrameLive()) {
+    // Instruct the destination render frame host to set up a Mojo connection
+    // with the new render frame if necessary.
+    dest_render_frame_host->SetUpMojoIfNeeded();

[nasko, 2014/10/23 15:59:08]

This should move below the InitRenderView call.

[blundell, 2014/10/24 14:42:55]

It's actually important that this be before that call. When the render process
dies on a WebUI site and then a reload occurs, the call to InitRenderView()
indirectly ends up in the //chrome Mojo WebUI code adding the relevant
MojoWebUIController as a Mojo service to the RFH's ServiceRegistry. Thus, the
ServiceRegistry needs to be set up before that flow occurs.

[nasko, 2014/10/24 16:13:11]

Ok. This seems to be important enough that some of the explanation would be good
to be in the comment before the call.

[Charlie Reis, 2014/10/24 16:30:45]

+1.

+
     // Recreate the opener chain.
     int opener_route_id = delegate_->CreateOpenerRenderViewsForRenderManager(
         dest_render_frame_host->GetSiteInstance());