Switch to double for time calculations using playback rate.

media/renderers/renderer_impl.h

Index: media/renderers/renderer_impl.h
diff --git a/media/renderers/renderer_impl.h b/media/renderers/renderer_impl.h
index feb69201ea4fe8353fda32b0431b39bbb6a507d1..55c37f5b0d83a50815cc61eac06cea93b130cc7e 100644
--- a/media/renderers/renderer_impl.h
+++ b/media/renderers/renderer_impl.h
@@ -56,7 +56,7 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
               const CdmAttachedCB& cdm_attached_cb) final;
   void Flush(const base::Closure& flush_cb) final;
   void StartPlayingFrom(base::TimeDelta time) final;
-  void SetPlaybackRate(float playback_rate) final;
+  void SetPlaybackRate(double playback_rate) final;
   void SetVolume(float volume) final;
   base::TimeDelta GetMediaTime() final;
   bool HasAudio() final;
@@ -154,7 +154,7 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   TimeSource* time_source_;
   scoped_ptr<WallClockTimeSource> wall_clock_time_source_;
   bool time_ticking_;
-  float playback_rate_;
+  double playback_rate_;
 
   // The time to start playback from after starting/seeking has completed.
   base::TimeDelta start_time_;