[Smart Lock] Add UMA metrics to measure duration of unlock.

chrome/browser/signin/easy_unlock_service_regular.h

 // Copyright 2014 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 CHROME_BROWSER_SIGNIN_EASY_UNLOCK_SERVICE_REGULAR_H_
 #define CHROME_BROWSER_SIGNIN_EASY_UNLOCK_SERVICE_REGULAR_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
+#include "base/time/time.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
 #include "chrome/browser/signin/screenlock_bridge.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/login/easy_unlock/short_lived_user_context.h"
+#include "chromeos/dbus/power_manager_client.h"
 #endif
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
 namespace cryptauth {
 class ToggleEasyUnlockResponse;
 }
 
 namespace proximity_auth {
 class CryptAuthClient;
 }
 
 class EasyUnlockAppManager;
 class EasyUnlockToggleFlow;
 class Profile;
 
 // EasyUnlockService instance that should be used for regular, non-signin
 // profiles.
 class EasyUnlockServiceRegular : public EasyUnlockService,
+#if defined(OS_CHROMEOS)
+                                 public chromeos::PowerManagerClient::Observer,

[Tim Song, 2015/03/25 18:17:28]

The base class has a similar observer in EasyUnlockService::PowerMonitor.
Perhaps you can call a virtual method from the base class when resuming from
suspend instead of adding this observer?

[Ilya Sherman, 2015/04/01 00:16:13]

Done.

+#endif
                                  public ScreenlockBridge::Observer {
  public:
   explicit EasyUnlockServiceRegular(Profile* profile);
   ~EasyUnlockServiceRegular() override;
 
  private:
   // EasyUnlockService implementation:
   EasyUnlockService::Type GetType() const override;
   std::string GetUserEmail() const override;
   void LaunchSetup() override;
@@ skipping 17 matching lines @@
   bool IsAllowedInternal() const override;
   void OnWillFinalizeUnlock(bool success) override;
 
   // ScreenlockBridge::Observer implementation:
   void OnScreenDidLock(
       ScreenlockBridge::LockHandler::ScreenType screen_type) override;
   void OnScreenDidUnlock(
       ScreenlockBridge::LockHandler::ScreenType screen_type) override;
   void OnFocusedUserChanged(const std::string& user_id) override;
 
+#if defined(OS_CHROMEOS)
+  // chromeos::PowerManagerClient::Observer implementation:
+  void SuspendDone(const base::TimeDelta& sleep_duration) override;
+#endif  // defined(OS_CHROMEOS)
+
   // Callback when the controlling pref changes.
   void OnPrefsChanged();
 
   // Sets the new turn-off flow status.
   void SetTurnOffFlowStatus(TurnOffFlowStatus status);
 
   // Callback for ToggleEasyUnlock CryptAuth API.
   void OnToggleEasyUnlockApiComplete(
       const cryptauth::ToggleEasyUnlockResponse& response);
   void OnToggleEasyUnlockApiFailed(const std::string& error_message);
@@ skipping 21 matching lines @@
   TurnOffFlowStatus turn_off_flow_status_;
   scoped_ptr<proximity_auth::CryptAuthClient> cryptauth_client_;
 
   AutoPairingResultCallback auto_pairing_callback_;
 
   // True if the user just unlocked the screen using Easy Unlock. Reset once
   // the screen unlocks. Used to distinguish Easy Unlock-powered unlocks from
   // password-based unlocks for metrics.
   bool will_unlock_using_easy_unlock_;
 
+  // The timestamp for the most recent time when the lock screen was shown. The
+  // lock screen is typically shown when the user awakens her computer from
+  // sleep -- e.g. by opening the lid -- but can also be shown if the screen is
+  // locked but the computer does not go to sleep.
+  base::TimeTicks lock_screen_last_shown_timestamp_;
+
   base::WeakPtrFactory<EasyUnlockServiceRegular> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EasyUnlockServiceRegular);
 };
 
 #endif  // CHROME_BROWSER_SIGNIN_EASY_UNLOCK_SERVICE_REGULAR_H_