Add status area to Aura builds.

ui/aura_shell/shell_delegate.h

Index: ui/aura_shell/shell_delegate.h
diff --git a/ui/aura_shell/shell_delegate.h b/ui/aura_shell/shell_delegate.h
index 1fdb7358c3acbe3b9229a3b79a0c154785e3e2ee..b31666970376c2d4b6b507760b85a8ba57578e94 100644
--- a/ui/aura_shell/shell_delegate.h
+++ b/ui/aura_shell/shell_delegate.h
@@ -8,6 +8,10 @@
 
 #include "ui/aura_shell/aura_shell_export.h"
 
+namespace views {
+class Widget;
+}
+
 namespace aura_shell {
 
 struct LauncherItem;
@@ -22,6 +26,9 @@ class AURA_SHELL_EXPORT ShellDelegate {
   // window.
   virtual void CreateNewWindow() = 0;
 
+  // Invoked to create a new status area. Can return NULL.
+  virtual views::Widget* CreateStatusArea() = 0;
+
   // Invoked when the user clicks the app list button on the launcher.
   virtual void ShowApps() = 0;