Removed NOTIFICATION_BROWSER_CLOSING notification

chrome/browser/ui/browser.cc

Index: chrome/browser/ui/browser.cc
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 832153b86e17201770479a2f4bfa17284c823b52..9e94f44ff407629aca9814f439e1704cbc6dbefa 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -746,11 +746,7 @@ void Browser::OnWindowClosing() {
   if (tab_restore_service && is_type_tabbed() && tab_strip_model_->count())
     tab_restore_service->BrowserClosing(live_tab_context());
 
-  // TODO(sky): convert session/tab restore to use notification.
-  content::NotificationService::current()->Notify(
-      chrome::NOTIFICATION_BROWSER_CLOSING,
-      content::Source<Browser>(this),
-      content::NotificationService::NoDetails());
+  BrowserList::NotifyBrowserCloseStarted(this);
 
   if (!IsFastTabUnloadEnabled())
     tab_strip_model_->CloseAllTabs();
@@ -2556,7 +2552,11 @@ bool Browser::ShouldHideUIForFullscreen() const {
 }
 
 bool Browser::ShouldStartShutdown() const {
-  return BrowserList::GetInstance()->size() <= 1;
+  DCHECK_GE(BrowserList::GetInstance()->size(),
+            BrowserList::GetInstance()->currently_closing_browsers_count());
+  // Start shutdown process only when closing the last browser.
+  return BrowserList::GetInstance()->size() ==
+         BrowserList::GetInstance()->currently_closing_browsers_count() + 1;
 }
 
 bool Browser::MaybeCreateBackgroundContents(