Keep browser process alive while there are platform apps with background pages running.

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"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/extensions/event_router.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/window_controller.h"
 #include "chrome/browser/file_select_helper.h"
+#include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_modal_dialogs/javascript_dialog_creator.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/view_type_utils.h"
 #include "chrome/common/chrome_constants.h"
@@ skipping 100 matching lines @@
                              SiteInstance* site_instance,
                              const GURL& url,
                              chrome::ViewType host_type)
     : extension_(extension),
       extension_id_(extension->id()),
       profile_(Profile::FromBrowserContext(
           site_instance->GetBrowserContext())),
       render_view_host_(NULL),
       did_stop_loading_(false),
       document_element_available_(false),
+      keeping_browser_process_alive_(false),
       initial_url_(url),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           extension_function_dispatcher_(profile_, this)),
       extension_host_type_(host_type),
       associated_web_contents_(NULL) {
   host_contents_.reset(WebContents::Create(
       profile_, site_instance, MSG_ROUTING_NONE, NULL));
   content::WebContentsObserver::Observe(host_contents_.get());
   host_contents_->SetDelegate(this);
   chrome::SetViewType(host_contents_.get(), host_type);
@@ skipping 12 matching lines @@
   if (extension_host_type_ == chrome::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE &&
       extension_ && extension_->has_lazy_background_page()) {
     UMA_HISTOGRAM_LONG_TIMES("Extensions.EventPageActiveTime",
                              since_created_.Elapsed());
   }
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED,
       content::Source<Profile>(profile_),
       content::Details<ExtensionHost>(this));
   ProcessCreationQueue::GetInstance()->Remove(this);
+
+  if (keeping_browser_process_alive_)
+    browser::EndKeepAlive();
 }
 
 void ExtensionHost::CreateView(Browser* browser) {
 #if defined(TOOLKIT_VIEWS)
   view_.reset(new ExtensionViewViews(this, browser));
   // We own |view_|, so don't auto delete when it's removed from the view
   // hierarchy.
   view_->set_owned_by_client();
 #elif defined(OS_MACOSX)
   view_.reset(new ExtensionViewMac(this, browser));
@@ skipping 276 matching lines @@
     pm->IncrementLazyKeepaliveCount(extension());
 }
 
 void ExtensionHost::DidCloseJavaScriptDialog() {
   ExtensionProcessManager* pm =
       ExtensionSystem::Get(profile_)->process_manager();
   if (pm)
     pm->DecrementLazyKeepaliveCount(extension());
 }
 
+void ExtensionHost::KeepBrowserProcessAlive() {

[Aaron Boodman, 2012/10/31 07:31:22]

Nit: I think SetKeepsBrowserProcessAlive() would be a bit more understandable.

[benwells, 2012/10/31 08:08:22]

Done.

+  if (keeping_browser_process_alive_)
+    return;
+
+  keeping_browser_process_alive_ = true;
+  browser::StartKeepAlive();
+}
+
 WebContents* ExtensionHost::OpenURLFromTab(WebContents* source,
                                            const OpenURLParams& params) {
   // Whitelist the dispositions we will allow to be opened.
   switch (params.disposition) {
     case SINGLETON_TAB:
     case NEW_FOREGROUND_TAB:
     case NEW_BACKGROUND_TAB:
     case NEW_POPUP:
     case NEW_WINDOW:
     case SAVE_TO_DISK:
@@ skipping 175 matching lines @@
 void ExtensionHost::RequestMediaAccessPermission(
     content::WebContents* web_contents,
     const content::MediaStreamRequest* request,
     const content::MediaResponseCallback& callback) {
   // For tab capture device, we require the tabCapture permission.
   RequestMediaAccessPermissionHelper::AuthorizeRequest(
       request, callback, extension(), false);
 }
 
 }  // namespace extensions