Activate the status area only when it's focused using the keyboard

ash/system/tray/system_tray.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.h"
 
 #include "ash/shell.h"
 #include "ash/shell/panel_window.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ skipping 330 matching lines @@
   bubble_->SetAlignment(views::BubbleBorder::ALIGN_EDGE_TO_ANCHOR_EDGE);
   popup_->non_client_view()->frame_view()->set_background(NULL);
   popup_->non_client_view()->frame_view()->set_border(
       new SystemTrayBubbleBorder(bubble_));
   popup_->AddObserver(this);
   bubble_->Show();
 }
 
 bool SystemTray::OnMousePressed(const views::MouseEvent& event) {
   if (popup_)
-    popup_->Show();
+    popup_->Hide();
   else
     ShowItems(items_, false);
   return true;
 }
 
 void SystemTray::OnMouseEntered(const views::MouseEvent& event) {
   static_cast<SystemTrayBackground*>(background())->set_hovering(true);
   SchedulePaint();
 }
 
 void SystemTray::OnMouseExited(const views::MouseEvent& event) {
   static_cast<SystemTrayBackground*>(background())->set_hovering(false);
   SchedulePaint();
 }
 
 void SystemTray::OnWidgetClosing(views::Widget* widget) {
   CHECK_EQ(popup_, widget);
   popup_ = NULL;
   bubble_ = NULL;
 }
 
 }  // namespace ash