Cast: Reshuffle files under media/cast

media/cast/base/clock_drift_smoother.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 "media/cast/base/clock_drift_smoother.h"
-
-#include "base/logging.h"
-
-namespace media {
-namespace cast {
-
-ClockDriftSmoother::ClockDriftSmoother(base::TimeDelta time_constant)
-    : time_constant_(time_constant),
-      estimate_us_(0.0) {
-  DCHECK(time_constant_ > base::TimeDelta());
-}
-
-ClockDriftSmoother::~ClockDriftSmoother() {}
-
-base::TimeDelta ClockDriftSmoother::Current() const {
-  DCHECK(!last_update_time_.is_null());
-  return base::TimeDelta::FromMicroseconds(
-      static_cast<int64>(estimate_us_ + 0.5));  // Round to nearest microsecond.
-}
-
-void ClockDriftSmoother::Reset(base::TimeTicks now,
-                               base::TimeDelta measured_offset) {
-  DCHECK(!now.is_null());
-  last_update_time_ = now;
-  estimate_us_ = measured_offset.InMicroseconds();
-}
-
-void ClockDriftSmoother::Update(base::TimeTicks now,
-                                base::TimeDelta measured_offset) {
-  DCHECK(!now.is_null());
-  if (last_update_time_.is_null()) {
-    Reset(now, measured_offset);
-  } else if (now < last_update_time_) {
-    // |now| is not monotonically non-decreasing.
-    NOTREACHED();
-  } else {
-    const double elapsed_us = (now - last_update_time_).InMicroseconds();
-    last_update_time_ = now;
-    const double weight =
-        elapsed_us / (elapsed_us + time_constant_.InMicroseconds());
-    estimate_us_ = weight * measured_offset.InMicroseconds() +
-        (1.0 - weight) * estimate_us_;
-  }
-}
-
-// static
-base::TimeDelta ClockDriftSmoother::GetDefaultTimeConstant() {
-  static const int kDefaultTimeConstantInSeconds = 30;
-  return base::TimeDelta::FromSeconds(kDefaultTimeConstantInSeconds);
-}
-
-}  // namespace cast
-}  // namespace media