It is time.

ui/compositor/layer_animator_collection.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/layer_animator_collection.h"
-
-#include <set>
-
-#include "base/time/time.h"
-#include "ui/compositor/compositor.h"
-#include "ui/compositor/layer_animator.h"
-#include "ui/gfx/frame_time.h"
-
-namespace ui {
-
-LayerAnimatorCollection::LayerAnimatorCollection(Compositor* compositor)
-    : compositor_(compositor), last_tick_time_(gfx::FrameTime::Now()) {
-}
-
-LayerAnimatorCollection::~LayerAnimatorCollection() {
-  if (compositor_ && compositor_->HasAnimationObserver(this))
-    compositor_->RemoveAnimationObserver(this);
-}
-
-void LayerAnimatorCollection::StartAnimator(
-    scoped_refptr<LayerAnimator> animator) {
-  DCHECK_EQ(0U, animators_.count(animator));
-  if (!animators_.size())
-    last_tick_time_ = gfx::FrameTime::Now();
-  animators_.insert(animator);
-  if (animators_.size() == 1U && compositor_)
-    compositor_->AddAnimationObserver(this);
-}
-
-void LayerAnimatorCollection::StopAnimator(
-    scoped_refptr<LayerAnimator> animator) {
-  DCHECK_GT(animators_.count(animator), 0U);
-  animators_.erase(animator);
-  if (animators_.empty() && compositor_)
-    compositor_->RemoveAnimationObserver(this);
-}
-
-bool LayerAnimatorCollection::HasActiveAnimators() const {
-  return !animators_.empty();
-}
-
-void LayerAnimatorCollection::OnAnimationStep(base::TimeTicks now) {
-  last_tick_time_ = now;
-  std::set<scoped_refptr<LayerAnimator> > list = animators_;
-  for (std::set<scoped_refptr<LayerAnimator> >::iterator iter = list.begin();
-       iter != list.end();
-       ++iter) {
-    // Make sure the animator is still valid.
-    if (animators_.count(*iter) > 0)
-      (*iter)->Step(now);
-  }
-  if (!HasActiveAnimators() && compositor_)
-    compositor_->RemoveAnimationObserver(this);
-}
-
-}  // namespace ui