Added UMA metrics for screen capture UI in the status area.

ash/common/system/chromeos/screen_security/screen_tray_item.h

 // Copyright 2013 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.
 
 #ifndef ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_
 
 #include <string>
 
 #include "ash/common/system/tray/system_tray_item.h"
@@ skipping 99 matching lines @@
   void Update();
   void Start(const base::Closure& stop_callback);
   void Stop();
 
   // Creates or updates the notification for the tray item.
   virtual void CreateOrUpdateNotification() = 0;
 
   // Returns the id of the notification for the tray item.
   virtual std::string GetNotificationId() = 0;
 
+  // Called after Stop() is invoked from the default view.
+  virtual void RecordStoppedFromDefaultViewMetric() = 0;
+
+  // Called after Stop() is invoked from the notification view.
+  virtual void RecordStoppedFromNotificationViewMetric() = 0;
+
   // Overridden from SystemTrayItem.
   views::View* CreateTrayView(LoginStatus status) override = 0;
   views::View* CreateDefaultView(LoginStatus status) override = 0;
   void DestroyTrayView() override;
   void DestroyDefaultView() override;
   void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
  private:
   tray::ScreenTrayView* tray_view_;
   tray::ScreenStatusView* default_view_;
   bool is_started_;
   base::Closure stop_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenTrayItem);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_SCREEN_SECURITY_SCREEN_TRAY_ITEM_H_