It is time.

ui/compositor/compositor_vsync_manager.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 "ui/compositor/compositor_vsync_manager.h"
-
-namespace ui {
-
-CompositorVSyncManager::CompositorVSyncManager()
-    : observer_list_(new ObserverListThreadSafe<Observer>()),
-      authoritative_vsync_interval_(base::TimeDelta::FromSeconds(0)) {}
-
-CompositorVSyncManager::~CompositorVSyncManager() {}
-
-void CompositorVSyncManager::SetAuthoritativeVSyncInterval(
-    base::TimeDelta interval) {
-  base::TimeTicks timebase;
-  {
-    base::AutoLock lock(vsync_parameters_lock_);
-    timebase = last_timebase_;
-    authoritative_vsync_interval_ = interval;
-    last_interval_ = interval;
-  }
-  NotifyObservers(timebase, interval);
-}
-
-void CompositorVSyncManager::UpdateVSyncParameters(base::TimeTicks timebase,
-                                                   base::TimeDelta interval) {
-  {
-    base::AutoLock lock(vsync_parameters_lock_);
-    if (authoritative_vsync_interval_ != base::TimeDelta::FromSeconds(0))
-      interval = authoritative_vsync_interval_;
-    last_timebase_ = timebase;
-    last_interval_ = interval;
-  }
-  NotifyObservers(timebase, interval);
-}
-
-void CompositorVSyncManager::AddObserver(Observer* observer) {
-  base::TimeTicks timebase;
-  base::TimeDelta interval;
-  {
-    base::AutoLock lock(vsync_parameters_lock_);
-    timebase = last_timebase_;
-    interval = last_interval_;
-  }
-  observer_list_->AddObserver(observer);
-  observer->OnUpdateVSyncParameters(timebase, interval);
-}
-
-void CompositorVSyncManager::RemoveObserver(Observer* observer) {
-  observer_list_->RemoveObserver(observer);
-}
-
-void CompositorVSyncManager::NotifyObservers(base::TimeTicks timebase,
-                                             base::TimeDelta interval) {
-  observer_list_->Notify(
-      &CompositorVSyncManager::Observer::OnUpdateVSyncParameters,
-      timebase,
-      interval);
-}
-
-}  // namespace ui