Removing unnecessary creation of RenderViewHostDestructionObserver for all WebContents

extensions/browser/process_manager.cc

 // Copyright 2013 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/process_manager.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 325 matching lines @@
   // Keepalive count, balanced in RegisterRenderViewHost.
   if (view_type != VIEW_TYPE_INVALID &&
       view_type != VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
     const Extension* extension = GetExtensionForRenderViewHost(
         render_view_host);
     if (extension)
       DecrementLazyKeepaliveCount(extension);
   }
 }
 
-void ProcessManager::RegisterRenderViewHost(RenderViewHost* render_view_host) {
+bool ProcessManager::RegisterRenderViewHost(RenderViewHost* render_view_host) {
   const Extension* extension = GetExtensionForRenderViewHost(
       render_view_host);
   if (!extension)
-    return;
+    return false;
 
   WebContents* web_contents = WebContents::FromRenderViewHost(render_view_host);
   all_extension_views_[render_view_host] = GetViewType(web_contents);
 
   // Keep the lazy background page alive as long as any non-background-page
   // extension views are visible. Keepalive count balanced in
   // UnregisterRenderViewHost.
   IncrementLazyKeepaliveCountForView(render_view_host);
+  return true;
 }
 
 SiteInstance* ProcessManager::GetSiteInstanceForURL(const GURL& url) {
   return site_instance_->GetRelatedSiteInstance(url);
 }
 
 bool ProcessManager::IsBackgroundHostClosing(const std::string& extension_id) {
   ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
   return (host && background_page_data_[extension_id].is_closing);
 }
@@ skipping 296 matching lines @@
         break;
 
       typedef std::pair<RenderViewHost*, RenderViewHost*> RVHPair;
       RVHPair* switched_details = content::Details<RVHPair>(details).ptr();
       if (switched_details->first)
         UnregisterRenderViewHost(switched_details->first);
 
       // The above will unregister a RVH when it gets swapped out with a new
       // one. However we need to watch the WebContents to know when a RVH is
       // deleted because the WebContents has gone away.
-      RenderViewHostDestructionObserver::CreateForWebContents(contents);
-      RegisterRenderViewHost(switched_details->second);
+      if (RegisterRenderViewHost(switched_details->second)) {
+        RenderViewHostDestructionObserver::CreateForWebContents(contents);
+      }
       break;
     }
 
     case content::NOTIFICATION_WEB_CONTENTS_CONNECTED: {
       WebContents* contents = content::Source<WebContents>(source).ptr();
       if (contents->GetBrowserContext() != GetBrowserContext())
         break;
       const Extension* extension = GetExtensionForRenderViewHost(
           contents->GetRenderViewHost());
       if (!extension)
@@ skipping 197 matching lines @@
     const Extension* extension =
         registry->enabled_extensions().GetExtensionOrAppByURL(url);
     if (extension && !IncognitoInfo::IsSplitMode(extension)) {
       return original_manager_->GetSiteInstanceForURL(url);
     }
   }
   return ProcessManager::GetSiteInstanceForURL(url);
 }
 
 }  // namespace extensions