Adding new user menu section to the SystemTrayMenu & refactoring of user access

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 9112130ab35c684dcd280cd591cf5f7ceb78b5e6..1e75bab37316800d9176672c764c33e318bf1c77 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -616,7 +616,7 @@ void Shell::Init() {
 
 void Shell::ShowContextMenu(const gfx::Point& location_in_screen) {
   // No context menus if there is no session with an active user.
-  if (!session_state_delegate_->HasActiveUser())
+  if (!session_state_delegate_->NumberOfLoggedInUsers())
     return;
   // No context menus when screen is locked.
   if (session_state_delegate_->IsScreenLocked())