cros: Add enterprise user session metrics

chrome/browser/chromeos/session_length_limiter.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 "chrome/browser/chromeos/session_length_limiter.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 89 matching lines @@
 
   if (!user_activity_seen_ && ui::UserActivityDetector::Get())
     ui::UserActivityDetector::Get()->AddObserver(this);
 }
 
 SessionLengthLimiter::~SessionLengthLimiter() {
   if (!user_activity_seen_ && ui::UserActivityDetector::Get())
     ui::UserActivityDetector::Get()->RemoveObserver(this);
 }
 
+base::TimeDelta SessionLengthLimiter::GetSessionDuration() const {
+  if (session_start_time_.is_null())
+    return base::TimeDelta();
+
+  return delegate_->GetCurrentTime() - session_start_time_;
+}
+
 void SessionLengthLimiter::OnUserActivity(const ui::Event* event) {
   if (user_activity_seen_)
     return;
   if (ui::UserActivityDetector::Get())
     ui::UserActivityDetector::Get()->RemoveObserver(this);
   user_activity_seen_ = true;
 
   PrefService* local_state = g_browser_process->local_state();
   local_state->SetBoolean(prefs::kSessionUserActivitySeen, true);
   if (session_start_time_.is_null()) {
@@ skipping 84 matching lines @@
     return;
   }
 
   // Set a timer to log out the user when the session length limit is reached.
   timer_.reset(new base::OneShotTimer);
   timer_->Start(FROM_HERE, remaining, delegate_.get(),
                 &SessionLengthLimiter::Delegate::StopSession);
 }
 
 }  // namespace chromeos