UMA track signed in duration at signout

components/signin/core/browser/signin_manager_base.cc

 // 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.
 
 #include "components/signin/core/browser/signin_manager_base.h"
 
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 72 matching lines @@
   DCHECK(pref_username.empty() || gaia::AreEmailsSame(username, pref_username))
       << "username: " << username << "; pref_username: " << pref_username;
   authenticated_username_ = username;
   client_->GetPrefs()->SetString(prefs::kGoogleServicesUsername, username);
   NotifyDiagnosticsObservers(USERNAME, username);
 
   // Go ahead and update the last signed in username here as well. Once a
   // user is signed in the two preferences should match. Doing it here as
   // opposed to on signin allows us to catch the upgrade scenario.
   client_->GetPrefs()->SetString(prefs::kGoogleServicesLastUsername, username);
+  client_->GetPrefs()->SetInt64(prefs::kSignedInTime,
+                                base::Time::Now().ToInternalValue());

[Roger Tawa OOO till Jul 10th, 2014/08/12 14:14:52]

Seems like it would be better to put this in OnSignedIn(), right before the call
to SetAuthenticatedUsername().

[Mike Lerman, 2014/08/12 18:07:10]

Done.

 }
 
 void SigninManagerBase::clear_authenticated_username() {
   authenticated_username_.clear();
 }
 
 bool SigninManagerBase::AuthInProgress() const {
   // SigninManagerBase never kicks off auth processes itself.
   return false;
 }
@@ skipping 26 matching lines @@
                     NotifySigninValueChanged(field, value));
 }
 
 void SigninManagerBase::NotifyDiagnosticsObservers(
     const TimedSigninStatusField& field,
     const std::string& value) {
   FOR_EACH_OBSERVER(SigninDiagnosticsObserver,
                     signin_diagnostics_observers_,
                     NotifySigninValueChanged(field, value));
 }