views: Do not set capture on a widget if it cannot be activated.

ash/system/tray/system_tray_widget_delegate.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 "ash/system/tray/system_tray_widget_delegate.h"
 
 #include "ash/ash_export.h"
 #include "ash/focus_cycler.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 41 matching lines @@
 
 const views::Widget* StatusAreaView::GetWidget() const {
   return View::GetWidget();
 }
 
 bool StatusAreaView::CanActivate() const {
   // We don't want mouse clicks to activate us, but we need to allow
   // activation when the user is using the keyboard (FocusCycler).
   const FocusCycler* focus_cycler = focus_cycler_for_testing_ ?
       focus_cycler_for_testing_ : Shell::GetInstance()->focus_cycler();
-  return focus_cycler->widget_activating() == GetWidget();
+  return focus_cycler && focus_cycler->widget_activating() == GetWidget();
 }
 
 void StatusAreaView::DeleteDelegate() {
 }
 
 }  // namespace internal
 }  // namespace ash