Switch to double for time calculations using playback rate.

media/mojo/services/mojo_renderer_service.cc

Index: media/mojo/services/mojo_renderer_service.cc
diff --git a/media/mojo/services/mojo_renderer_service.cc b/media/mojo/services/mojo_renderer_service.cc
index 7b6884d93b753b2c0e03a156031f1ab574ec6505..d86b2c5b33f54a8fe60d2e97af5d9e7eb8f9e20c 100644
--- a/media/mojo/services/mojo_renderer_service.cc
+++ b/media/mojo/services/mojo_renderer_service.cc
@@ -94,7 +94,7 @@ void MojoRendererService::StartPlayingFrom(int64_t time_delta_usec) {
   SchedulePeriodicMediaTimeUpdates();
 }
 
-void MojoRendererService::SetPlaybackRate(float playback_rate) {
+void MojoRendererService::SetPlaybackRate(double playback_rate) {
   DVLOG(2) << __FUNCTION__ << ": " << playback_rate;
   DCHECK_EQ(state_, STATE_PLAYING);
   renderer_->SetPlaybackRate(playback_rate);