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

cc/scheduler/begin_frame_tracker.cc

Index: cc/scheduler/begin_frame_tracker.cc
diff --git a/cc/scheduler/begin_frame_tracker.cc b/cc/scheduler/begin_frame_tracker.cc
deleted file mode 100644
index fcc3313e6c9a0b65d58b41de889feeea2681bae0..0000000000000000000000000000000000000000
--- a/cc/scheduler/begin_frame_tracker.cc
+++ /dev/null
@@ -1,121 +0,0 @@
-// 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 "cc/scheduler/begin_frame_tracker.h"
-
-namespace cc {
-
-BeginFrameTracker::BeginFrameTracker(const tracked_objects::Location& location)
-    : location_(location),
-      location_string_(location.ToString()),
-      current_updated_at_(),
-      current_args_(),
-      current_finished_at_(base::TimeTicks::FromInternalValue(-1)) {
-}
-
-BeginFrameTracker::~BeginFrameTracker() {
-}
-
-void BeginFrameTracker::Start(BeginFrameArgs new_args) {
-  // Trace the frame time being passed between BeginFrameTrackers.
-  TRACE_EVENT_FLOW_STEP0(
-      TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"), "BeginFrameArgs",
-      new_args.frame_time.ToInternalValue(), location_string_);
-
-  // Trace this specific begin frame tracker Start/Finish times.
-  TRACE_EVENT_ASYNC_BEGIN2(
-      TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"),
-      location_string_.c_str(), new_args.frame_time.ToInternalValue(),
-      "new args", new_args.AsValue(), "current args", current_args_.AsValue());
-
-  // Check the new BeginFrameArgs are valid and monotonically increasing.
-  DCHECK(new_args.IsValid());
-  DCHECK_LE(current_args_.frame_time, new_args.frame_time);
-
-  DCHECK(HasFinished())
-      << "Tried to start a new frame before finishing an existing frame.";
-  current_updated_at_ = base::TimeTicks::NowFromSystemTraceTime();
-  current_args_ = new_args;
-  current_finished_at_ = base::TimeTicks();
-
-  // TODO(mithro): Add UMA tracking of delta between current_updated_at_ time
-  // and the new_args.frame_time argument. This will give us how long after a
-  // BeginFrameArgs message was created before we started processing it.
-}
-
-const BeginFrameArgs& BeginFrameTracker::Current() const {
-  DCHECK(!HasFinished())
-      << "Tried to use BeginFrameArgs after marking the frame finished.";
-  DCHECK(current_args_.IsValid())
-      << "Tried to use BeginFrameArgs before starting a frame!";
-  return current_args_;
-}
-
-void BeginFrameTracker::Finish() {
-  DCHECK(!HasFinished()) << "Tried to finish an already finished frame";
-  current_finished_at_ = base::TimeTicks::NowFromSystemTraceTime();
-  TRACE_EVENT_ASYNC_END0(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"),
-                         location_string_.c_str(),
-                         current_args_.frame_time.ToInternalValue());
-}
-
-const BeginFrameArgs& BeginFrameTracker::Last() const {
-  DCHECK(current_args_.IsValid())
-      << "Tried to use last BeginFrameArgs before starting a frame!";
-  DCHECK(HasFinished())
-      << "Tried to use last BeginFrameArgs before the frame is finished.";
-  return current_args_;
-}
-
-base::TimeDelta BeginFrameTracker::Interval() const {
-  base::TimeDelta interval = current_args_.interval;
-  // Normal interval will be ~16ms, 200Hz (5ms) screens are the fastest
-  // easily available so anything less than that is likely an error.
-  if (interval < base::TimeDelta::FromMilliseconds(1)) {
-    interval = BeginFrameArgs::DefaultInterval();
-  }
-  return interval;
-}
-
-void BeginFrameTracker::AsValueInto(
-    base::TimeTicks now,
-    base::trace_event::TracedValue* state) const {
-  state->SetInteger("updated_at_us", current_updated_at_.ToInternalValue());
-  state->SetInteger("finished_at_us", current_finished_at_.ToInternalValue());
-  if (HasFinished()) {
-    state->SetString("state", "FINISHED");
-    state->BeginDictionary("current_args_");
-  } else {
-    state->SetString("state", "USING");
-    state->BeginDictionary("last_args_");
-  }
-  current_args_.AsValueInto(state);
-  state->EndDictionary();
-
-  base::TimeTicks frame_time = current_args_.frame_time;
-  base::TimeTicks deadline = current_args_.deadline;
-  base::TimeDelta interval = current_args_.interval;
-  state->BeginDictionary("major_timestamps_in_ms");
-  state->SetDouble("0_interval", interval.InMillisecondsF());
-  state->SetDouble("1_now_to_deadline", (deadline - now).InMillisecondsF());
-  state->SetDouble("2_frame_time_to_now", (now - frame_time).InMillisecondsF());
-  state->SetDouble("3_frame_time_to_deadline",
-                   (deadline - frame_time).InMillisecondsF());
-  state->SetDouble("4_now", (now - base::TimeTicks()).InMillisecondsF());
-  state->SetDouble("5_frame_time",
-                   (frame_time - base::TimeTicks()).InMillisecondsF());
-  state->SetDouble("6_deadline",
-                   (deadline - base::TimeTicks()).InMillisecondsF());
-  state->EndDictionary();
-}
-
-const BeginFrameArgs& BeginFrameTracker::DangerousMethodCurrentOrLast() const {
-  if (!HasFinished()) {
-    return Current();
-  } else {
-    return Last();
-  }
-}
-
-}  // namespace cc