chromeos: Convert system tray session length limit to mojo

ash/session/session_controller.cc

 // 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.
 
 #include "ash/session/session_controller.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "ash/public/interfaces/user_info.mojom.h"
@@ skipping 262 matching lines @@
   if (Shell::HasInstance())
     Shell::Get()->lock_state_controller()->OnLockScreenHide(
         std::move(callback));
 }
 
 void SessionController::NotifyChromeTerminating() {
   for (auto& observer : observers_)
     observer.OnChromeTerminating();
 }
 
+void SessionController::SetSessionLengthLimit(base::TimeDelta length_limit,
+                                              base::TimeTicks start_time) {
+  session_length_limit_ = length_limit;
+  session_start_time_ = start_time;
+  for (auto& observer : observers_)
+    observer.OnSessionLengthLimitChanged();
+}
+
 void SessionController::ClearUserSessionsForTest() {
   user_sessions_.clear();
 }
 
 void SessionController::FlushMojoForTest() {
   client_.FlushForTesting();
 }
 
 void SessionController::LockScreenAndFlushForTest() {
   LockScreen();
@@ skipping 97 matching lines @@
   for (auto& observer : observers_)
     observer.OnLoginStatusChanged(login_status_);
 }
 
 void SessionController::OnLockAnimationFinished() {
   if (!start_lock_callback_.is_null())
     std::move(start_lock_callback_).Run(true /* locked */);
 }
 
 }  // namespace ash