Switch to double for time calculations using playback rate.

chromecast/media/base/switching_media_renderer.cc

Index: chromecast/media/base/switching_media_renderer.cc
diff --git a/chromecast/media/base/switching_media_renderer.cc b/chromecast/media/base/switching_media_renderer.cc
index 1ca45b235603605d5811c0bbff2fd05deddffe8b..8f73b7dec8e078a18f084baab5a940f8ff34df47 100644
--- a/chromecast/media/base/switching_media_renderer.cc
+++ b/chromecast/media/base/switching_media_renderer.cc
@@ -79,7 +79,7 @@ void SwitchingMediaRenderer::StartPlayingFrom(base::TimeDelta time) {
   GetRenderer()->StartPlayingFrom(time);
 }
 
-void SwitchingMediaRenderer::SetPlaybackRate(float playback_rate)  {
+void SwitchingMediaRenderer::SetPlaybackRate(double playback_rate)  {
   GetRenderer()->SetPlaybackRate(playback_rate);
 }