This defers starting background extension page RenderViews

chrome/browser/extensions/extension_host.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/extension_host.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/memory/singleton.h"
@@ skipping 66 matching lines @@
   static ProcessCreationQueue* GetInstance() {
     return Singleton<ProcessCreationQueue>::get();
   }
 
   // Add a host to the queue for RenderView creation.
   void CreateSoon(ExtensionHost* host) {
     queue_.push_back(host);
     PostTask();
   }
 
+  void DeferCreation(ExtensionHost* host) {
+    deferred_queue_.push_back(host);
+  }
+
+  void CreateDeferredRenderViews() {
+    queue_.splice(queue_.end(), deferred_queue_);
+    PostTask();
+  }
+
   // Remove a host from the queue (in case it's being deleted).
   void Remove(ExtensionHost* host) {
     Queue::iterator it = std::find(queue_.begin(), queue_.end(), host);
     if (it != queue_.end())
       queue_.erase(it);
+    it = std::find(deferred_queue_.begin(), deferred_queue_.end(), host);
+    if (it != deferred_queue_.end())
+      deferred_queue_.erase(it);
   }
 
  private:
   friend class Singleton<ProcessCreationQueue>;
   friend struct DefaultSingletonTraits<ProcessCreationQueue>;
   ProcessCreationQueue()
       : pending_create_(false),
         ptr_factory_(this) {}
 
   // Queue up a delayed task to process the next ExtensionHost in the queue.
@@ skipping 14 matching lines @@
 
     queue_.front()->CreateRenderViewNow();
     queue_.pop_front();
 
     if (!queue_.empty())
       PostTask();
   }
 
   typedef std::list<ExtensionHost*> Queue;
   Queue queue_;
+  Queue deferred_queue_;
   bool pending_create_;
   base::WeakPtrFactory<ProcessCreationQueue> ptr_factory_;
 };
 
 ////////////////
 // ExtensionHost
 
 ExtensionHost::ExtensionHost(const Extension* extension,
                              SiteInstance* site_instance,
                              const GURL& url,
@@ skipping 88 matching lines @@
 }
 
 bool ExtensionHost::IsRenderViewLive() const {
   return render_view_host()->IsRenderViewLive();
 }
 
 void ExtensionHost::CreateRenderViewSoon() {
   if ((render_process_host() && render_process_host()->HasConnection())) {
     // If the process is already started, go ahead and initialize the RenderView
     // synchronously. The process creation is the real meaty part that we want
+    // to rate limit.
+    CreateRenderViewNow();
+  } else {
+      ProcessCreationQueue::GetInstance()->CreateSoon(this);
+  }
+}
+
+void ExtensionHost::CreateRenderViewDeferred() {
+  if ((render_process_host() && render_process_host()->HasConnection())) {
+    // If the process is already started, go ahead and initialize the RenderView
+    // synchronously. The process creation is the real meaty part that we want
     // to defer.
     CreateRenderViewNow();
   } else {
-    ProcessCreationQueue::GetInstance()->CreateSoon(this);
+      ProcessCreationQueue::GetInstance()->DeferCreation(this);
   }
 }
 
+// static
+void ExtensionHost::CreateDeferredRenderViews() {
+  ProcessCreationQueue::GetInstance()->CreateDeferredRenderViews();
+}
+
 void ExtensionHost::CreateRenderViewNow() {
   LoadInitialURL();
   if (is_background_page()) {
     DCHECK(IsRenderViewLive());
     ExtensionSystem::Get(profile_)->extension_service()->
         DidCreateRenderViewForBackgroundPage(this);
   }
 }
 
 WindowController* ExtensionHost::GetExtensionWindowController() const {
@@ skipping 418 matching lines @@
 
 void ExtensionHost::RequestMediaAccessPermission(
     content::WebContents* web_contents,
     const content::MediaStreamRequest& request,
     const content::MediaResponseCallback& callback) {
   MediaCaptureDevicesDispatcher::GetInstance()->ProcessMediaAccessRequest(
       web_contents, request, callback, extension());
 }
 
 }  // namespace extensions