[Merge M60] arc: Provide metric to monitor Play Store window is shown time.

chrome/browser/chromeos/arc/arc_optin_uma.h

 // Copyright 2016 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_CHROMEOS_ARC_ARC_OPTIN_UMA_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_ARC_OPTIN_UMA_H_
 
 #include <ostream>
 
 #include "components/arc/common/auth.mojom.h"
@@ skipping 168 matching lines @@
 };
 
 void UpdateOptInActionUMA(OptInActionType type);
 void UpdateOptInCancelUMA(OptInCancelReason reason);
 void UpdateOptInFlowResultUMA(OptInFlowResult result);
 void UpdateEnabledStateUMA(bool enabled);
 void UpdateProvisioningResultUMA(ProvisioningResult result, bool managed);
 void UpdateProvisioningTiming(const base::TimeDelta& elapsed_time,
                               bool success,
                               bool managed);
+void UpdatePlayStoreShowTime(const base::TimeDelta& elapsed_time, bool managed);
 void UpdateSilentAuthCodeUMA(OptInSilentAuthCode state);
 void UpdateAuthTiming(const char* histogram_name, base::TimeDelta elapsed_time);
 void UpdateAuthCheckinAttempts(int32_t num_attempts);
 void UpdateAuthAccountCheckStatus(mojom::AccountCheckStatus status);
 
 // Outputs the stringified |result| to |os|. This is only for logging purposes.
 std::ostream& operator<<(std::ostream& os, const ProvisioningResult& result);
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_OPTIN_UMA_H_