Remove the RenderProcessHost observer and attach the WebContentsObserver earlier to the GuestView.

extensions/browser/guest_view/guest_view_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/guest_view/guest_view_manager.h"
 
 #include "base/strings/stringprintf.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 113 matching lines @@
     callback.Run(NULL);
     return;
   }
   guest->Init(
       embedder_extension_id, embedder_web_contents, create_params, callback);
 }
 
 content::WebContents* GuestViewManager::CreateGuestWithWebContentsParams(
     const std::string& view_type,
     const std::string& embedder_extension_id,
-    int embedder_render_process_id,
+    content::WebContents* embedder_web_contents,
     const content::WebContents::CreateParams& create_params) {
   int guest_instance_id = GetNextInstanceID();
   GuestViewBase* guest =
       GuestViewBase::Create(context_, guest_instance_id, view_type);
   if (!guest)
     return NULL;
   content::WebContents::CreateParams guest_create_params(create_params);
   guest_create_params.guest_delegate = guest;
   content::WebContents* guest_web_contents =
       WebContents::Create(guest_create_params);
+  int embedder_render_process_id =
+      embedder_web_contents->GetRenderProcessHost()->GetID();
   guest->InitWithWebContents(embedder_extension_id,
                              embedder_render_process_id,
+                             embedder_web_contents,
                              guest_web_contents);
   return guest_web_contents;
 }
 
 content::WebContents* GuestViewManager::GetGuestByInstanceID(
     content::WebContents* embedder_web_contents,
     int element_instance_id) {
   int guest_instance_id = GetGuestInstanceIDForElementID(embedder_web_contents,
                                                          element_instance_id);
   if (guest_instance_id == guestview::kInstanceIDNone)
@@ skipping 139 matching lines @@
     return true;
 
   GuestViewBase* guest_view = GuestViewBase::FromWebContents(it->second);
   if (!guest_view)
     return false;
 
   return embedder_render_process_id == guest_view->embedder_render_process_id();
 }
 
 }  // namespace extensions