Switch to double for time calculations using playback rate.

media/base/wall_clock_time_source.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/base/wall_clock_time_source.h"
 
 #include "base/logging.h"
 #include "base/time/default_tick_clock.h"
 
 namespace media {
 
 WallClockTimeSource::WallClockTimeSource()
     : tick_clock_(new base::DefaultTickClock()),
       ticking_(false),
-      playback_rate_(1.0f) {
+      playback_rate_(1.0) {
 }
 
 WallClockTimeSource::~WallClockTimeSource() {
 }
 
 void WallClockTimeSource::StartTicking() {
   DVLOG(1) << __FUNCTION__;
   base::AutoLock auto_lock(lock_);
   DCHECK(!ticking_);
   ticking_ = true;
   reference_wall_ticks_ = tick_clock_->NowTicks();
 }
 
 void WallClockTimeSource::StopTicking() {
   DVLOG(1) << __FUNCTION__;
   base::AutoLock auto_lock(lock_);
   DCHECK(ticking_);
   base_time_ = CurrentMediaTime_Locked();
   ticking_ = false;
   reference_wall_ticks_ = tick_clock_->NowTicks();
 }
 
-void WallClockTimeSource::SetPlaybackRate(float playback_rate) {
+void WallClockTimeSource::SetPlaybackRate(double playback_rate) {
   DVLOG(1) << __FUNCTION__ << "(" << playback_rate << ")";
   base::AutoLock auto_lock(lock_);
   // Estimate current media time using old rate to use as a new base time for
   // the new rate.
   if (ticking_) {
     base_time_ = CurrentMediaTime_Locked();
     reference_wall_ticks_ = tick_clock_->NowTicks();
   }
 
   playback_rate_ = playback_rate;
@@ skipping 32 matching lines @@
   if (!ticking_ || playback_rate_ == 0.0)
     return base_time_;
 
   base::TimeTicks now = tick_clock_->NowTicks();
   return base_time_ +
          base::TimeDelta::FromMicroseconds(
              (now - reference_wall_ticks_).InMicroseconds() * playback_rate_);
 }
 
 }  // namespace media