[Cast] Repair receiver playout time calculations and frame skip logic.

media/cast/test/skewed_tick_clock.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/test/skewed_tick_clock.h"
 
 #include "base/time/time.h"
 
 namespace media {
 namespace cast {
 namespace test {
 
 SkewedTickClock::SkewedTickClock(base::TickClock* clock)
     : clock_(clock),
       skew_(1.0),
       last_skew_set_time_(clock_->NowTicks()),
       skew_clock_at_last_set_(last_skew_set_time_) {
 }
 
 base::TimeTicks SkewedTickClock::SkewTicks(base::TimeTicks now) {
   return base::TimeDelta::FromMicroseconds(
       (now - last_skew_set_time_).InMicroseconds() * skew_) +
       skew_clock_at_last_set_;
 }
 
 void SkewedTickClock::SetSkew(double skew, base::TimeDelta offset) {
   base::TimeTicks now = clock_->NowTicks();
+  skew_clock_at_last_set_ = SkewTicks(now) + offset;
+  skew_ = skew;
   last_skew_set_time_ = now;
-  skew_clock_at_last_set_ = SkewTicks(now) + offset;
 }
 
 base::TimeTicks SkewedTickClock::NowTicks() {
   return SkewTicks(clock_->NowTicks());
 }
 
 }  // namespace test
 }  // namespace cast
 }  // namespace media