Revert of cc: Adding BeginFrameTracker object and removing Now() from LTHI.

cc/trees/layer_tree_impl.cc

 // Copyright 2011 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 "cc/trees/layer_tree_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 860 matching lines @@
 }
 
 bool LayerTreeImpl::PinchGestureActive() const {
   return layer_tree_host_impl_->pinch_gesture_active();
 }
 
 BeginFrameArgs LayerTreeImpl::CurrentBeginFrameArgs() const {
   return layer_tree_host_impl_->CurrentBeginFrameArgs();
 }
 
-base::TimeDelta LayerTreeImpl::CurrentBeginFrameInterval() const {
-  return layer_tree_host_impl_->CurrentBeginFrameInterval();
+base::TimeDelta LayerTreeImpl::begin_impl_frame_interval() const {
+  return layer_tree_host_impl_->begin_impl_frame_interval();
 }
 
 void LayerTreeImpl::SetNeedsCommit() {
   layer_tree_host_impl_->SetNeedsCommit();
 }
 
 gfx::Rect LayerTreeImpl::DeviceViewport() const {
   return layer_tree_host_impl_->DeviceViewport();
 }
 
@@ skipping 672 matching lines @@
     scoped_ptr<PendingPageScaleAnimation> pending_animation) {
   pending_page_scale_animation_ = pending_animation.Pass();
 }
 
 scoped_ptr<PendingPageScaleAnimation>
     LayerTreeImpl::TakePendingPageScaleAnimation() {
   return pending_page_scale_animation_.Pass();
 }
 
 }  // namespace cc