Make UserActivityDetector a singleton

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 "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/common/pref_names.h"
 #include "ui/events/event.h"
@@ skipping 71 matching lines @@
   // If this is a browser restart after a crash, try to restore the session
   // start time and the boolean indicating user activity from local state. If
   // this is not a browser restart after a crash or the attempt to restore
   // fails, set  the session start time to the current time and clear the
   // boolean indicating user activity.
   if (!browser_restarted || !RestoreStateAfterCrash()) {
     local_state->ClearPref(prefs::kSessionUserActivitySeen);
     UpdateSessionStartTime();
   }
 
-  if (!user_activity_seen_ && ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!user_activity_seen_ && wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->AddObserver(this);
 }
 
 SessionLengthLimiter::~SessionLengthLimiter() {
-  if (!user_activity_seen_ && ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (!user_activity_seen_ && wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->RemoveObserver(this);
 }
 
 void SessionLengthLimiter::OnUserActivity(const ui::Event* event) {
   if (user_activity_seen_)
     return;
-  if (ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (wm::UserActivityDetector::Get())
+    wm::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()) {
     // If instructed to wait for initial user activity and this is the first
     // activity in the session, set the session start time to the current time
     // and persist it in local state.
     session_start_time_ = delegate_->GetCurrentTime();
     local_state->SetInt64(prefs::kSessionStartTime,
@@ skipping 79 matching lines @@
     return;
   }
 
   // Set a timer to log out the user when the session length limit is reached.
   timer_.reset(new base::OneShotTimer<SessionLengthLimiter::Delegate>);
   timer_->Start(FROM_HERE, remaining, delegate_.get(),
                 &SessionLengthLimiter::Delegate::StopSession);
 }
 
 }  // namespace chromeos