Remove gfx::FrameTime for a single clock source

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()) {
+    : compositor_(compositor), last_tick_time_(base::TimeTicks::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();
+    last_tick_time_ = base::TimeTicks::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_)
@@ skipping 12 matching lines @@
        ++iter) {
     // Make sure the animator is still valid.
     if (animators_.count(*iter) > 0)
       (*iter)->Step(now);
   }
   if (!HasActiveAnimators() && compositor_)
     compositor_->RemoveAnimationObserver(this);
 }
 
 }  // namespace ui