ash: Add UMA action metrics for Ctrl-Shift-Q

ash/accelerators/accelerator_controller.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/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <iostream>
 #include <string>
@@ skipping 564 matching lines @@
       return false;
     }
     case DISABLE_GPU_WATCHDOG:
       content::GpuDataManager::GetInstance()->DisableGpuWatchdog();
       return true;
 #endif
     case OPEN_FEEDBACK_PAGE:
       ash::Shell::GetInstance()->delegate()->OpenFeedbackPage();
       return true;
     case EXIT:
+      // UMA metrics are recorded in the handler.
       exit_warning_handler_.HandleAccelerator();
       return true;
     case NEW_INCOGNITO_WINDOW:
       Shell::GetInstance()->delegate()->NewWindow(true /* is_incognito */);
       return true;
     case NEW_TAB:
       if (key_code == ui::VKEY_T)
         shell->delegate()->RecordUserMetricsAction(UMA_ACCEL_NEWTAB_T);
       Shell::GetInstance()->delegate()->NewTab();
       return true;
@@ skipping 369 matching lines @@
     keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       keyboard_brightness_control_delegate.Pass();
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash