Update signature of RFHM::CreateRenderFrameProxy.

It used to return the routing_id of the RenderFrameProxyHost for which a
RenderFrameProxy was initialized. This is a bit arbitrary and as a
result, among 6 callers, nobody was using it, except BrowserPluginHost.
It is probably better to return nothing instead.

Bug: None.
Change-Id: Idcc46d469f3eae53cabd5d09fa29636165804b69
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1614177
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661320}

content/browser/browser_plugin/browser_plugin_guest.cc

@@ -171,14 +171,14 @@ int BrowserPluginGuest::GetGuestProxyRoutingID() {
   SiteInstance* owner_site_instance = delegate_->GetOwnerSiteInstance();
   if (!owner_site_instance)
     return MSG_ROUTING_NONE;
-  int proxy_routing_id = GetWebContents()
-                             ->GetFrameTree()
-                             ->root()
-                             ->render_manager()
-                             ->CreateRenderFrameProxy(owner_site_instance);
-  guest_proxy_routing_id_ = RenderFrameProxyHost::FromID(
-      owner_site_instance->GetProcess()->GetID(), proxy_routing_id)
-          ->GetRenderViewHost()->GetRoutingID();
+
+  RenderFrameHostManager* rfh_manager =
+      GetWebContents()->GetFrameTree()->root()->render_manager();
+  rfh_manager->CreateRenderFrameProxy(owner_site_instance);
+  guest_proxy_routing_id_ =
+      rfh_manager->GetRenderFrameProxyHost(owner_site_instance)
+          ->GetRenderViewHost()
+          ->GetRoutingID();
 
   return guest_proxy_routing_id_;
 }

content/browser/frame_host/render_frame_host_manager.cc

@@ -2000,16 +2000,16 @@ std::unique_ptr<RenderFrameHostImpl> RenderFrameHostManager::CreateRenderFrame(
   return new_render_frame_host;
 }
 
-int RenderFrameHostManager::CreateRenderFrameProxy(SiteInstance* instance) {
+void RenderFrameHostManager::CreateRenderFrameProxy(SiteInstance* instance) {
   // A RenderFrameProxyHost should never be created in the same SiteInstance as
   // the current RFH.
   CHECK(instance);
   CHECK_NE(instance, render_frame_host_->GetSiteInstance());
 
-  // Return an already existing RenderFrameProxyHost if one exists and is alive.
+  // If a proxy already exists and is alive, nothing needs to be done.
   RenderFrameProxyHost* proxy = GetRenderFrameProxyHost(instance);
   if (proxy && proxy->is_render_frame_proxy_live())
-    return proxy->GetRoutingID();
+    return;
 
   // At this point we know that we either have to 1) create a new
   // RenderFrameProxyHost or 2) revive an existing, but no longer alive
@@ -2035,8 +2035,6 @@ int RenderFrameHostManager::CreateRenderFrameProxy(SiteInstance* instance) {
   } else {
     proxy->InitRenderFrameProxy();
   }
-
-  return proxy->GetRoutingID();
 }
 
 void RenderFrameHostManager::CreateProxiesForChildFrame(FrameTreeNode* child) {

content/browser/frame_host/render_frame_host_manager.h

@@ -297,9 +297,8 @@ class CONTENT_EXPORT RenderFrameHostManager
   std::unique_ptr<RenderFrameHostImpl> CreateRenderFrame(SiteInstance* instance,
                                                          bool hidden);
 
-  // Helper method to create and initialize a RenderFrameProxyHost and return
-  // its routing id.
-  int CreateRenderFrameProxy(SiteInstance* instance);
+  // Helper method to create and initialize a RenderFrameProxyHost.
+  void CreateRenderFrameProxy(SiteInstance* instance);
 
   // Creates proxies for a new child frame at FrameTreeNode |child| in all
   // SiteInstances for which the current frame has proxies.  This method is