Switch to double for time calculations using playback rate.

chromecast/media/cma/filters/cma_renderer.cc

Index: chromecast/media/cma/filters/cma_renderer.cc
diff --git a/chromecast/media/cma/filters/cma_renderer.cc b/chromecast/media/cma/filters/cma_renderer.cc
index 1473f02af0fc36c9b484b7b54b20d12a06161bb2..6a3db43793da998f09ca67f88a6b350800297fea 100644
--- a/chromecast/media/cma/filters/cma_renderer.cc
+++ b/chromecast/media/cma/filters/cma_renderer.cc
@@ -52,7 +52,7 @@ CmaRenderer::CmaRenderer(scoped_ptr<MediaPipeline> media_pipeline)
       initial_video_hole_created_(false),
       time_interpolator_(
           new ::media::TimeDeltaInterpolator(&default_tick_clock_)),
-      playback_rate_(1.0f),
+      playback_rate_(1.0),
       weak_factory_(this) {
   weak_this_ = weak_factory_.GetWeakPtr();
   thread_checker_.DetachFromThread();
@@ -183,7 +183,7 @@ void CmaRenderer::StartPlayingFrom(base::TimeDelta time) {
   CompleteStateTransition(kPlaying);
 }
 
-void CmaRenderer::SetPlaybackRate(float playback_rate) {
+void CmaRenderer::SetPlaybackRate(double playback_rate) {
   CMALOG(kLogControl) << __FUNCTION__ << ": " << playback_rate;
   DCHECK(thread_checker_.CalledOnValidThread());
   media_pipeline_->SetPlaybackRate(playback_rate);