Enable fast user switching in Win8/Ash mode.

chrome/browser/ui/browser_commands.cc

Index: chrome/browser/ui/browser_commands.cc
diff --git a/chrome/browser/ui/browser_commands.cc b/chrome/browser/ui/browser_commands.cc
index 0b7fc6ff931685c3a662b40cd43adffa8952761a..43db17c9199d31f5ca324ad39c6565c3cc3d7217 100644
--- a/chrome/browser/ui/browser_commands.cc
+++ b/chrome/browser/ui/browser_commands.cc
@@ -1061,6 +1061,12 @@ void ShowAvatarMenu(Browser* browser) {
       signin::ManageAccountsParams());
 }
 
+void ShowFastUserSwitcher(Browser* browser) {
+  browser->window()->ShowAvatarBubbleFromAvatarButton(
+      BrowserWindow::AVATAR_BUBBLE_MODE_FAST_USER_SWITCH,
+      signin::ManageAccountsParams());
+}
+
 void OpenUpdateChromeDialog(Browser* browser) {
   if (UpgradeDetector::GetInstance()->is_outdated_install()) {
     content::NotificationService::current()->Notify(