Set up Mojo connection when RenderFrameHost is reused for new RenderFrame

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index dbce027a974dc5122c61a0b02567e6b324cf4e97..d82e5c9bd8685c497ddd946522a05bc949a5f3e4 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -355,6 +355,14 @@ class CONTENT_EXPORT RenderFrameHostImpl
                         const CommonNavigationParams& common_params,
                         const CommitNavigationParams& commit_params);
 
+  // Sets up the Mojo connection between this instance and its associated render
+  // frame if it has not yet been set up.
+  void SetUpMojoIfNeeded();

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

nit: I don't see "IfNeeded" suffix adding much useful information. It is totally
fine if the method returns early if setup isn't needed.

[Charlie Reis, 2014/10/23 18:38:31]

I would be ok with keeping the IfNeeded part.  Not all setup methods can be
safely called multiple times, and there's precedent for it in content/ (even if
it's not universal).

[blundell, 2014/10/24 14:42:54]

Personally I like the |IfNeeded()|. Contrast this with RPHI::Init(), where every
callsite painstakingly comments that it is safe to call that method multiple
times.

+
+  // Tears down the browser-side state relating to the Mojo connection between
+  // this instance and its associated render frame.
+  void InvalidateMojoConnection();
+
  protected:
   friend class RenderFrameHostFactory;
 
@@ -549,7 +557,7 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // SiteInstance.
   scoped_ptr<TimeoutMonitor> swapout_event_monitor_timeout_;
 
-  ServiceRegistryImpl service_registry_;
+  scoped_ptr<ServiceRegistryImpl> service_registry_;
 
 #if defined(OS_ANDROID)
   scoped_ptr<ServiceRegistryAndroid> service_registry_android_;