Switch to double for time calculations using playback rate.

media/mojo/services/mojo_renderer_impl.cc

Index: media/mojo/services/mojo_renderer_impl.cc
diff --git a/media/mojo/services/mojo_renderer_impl.cc b/media/mojo/services/mojo_renderer_impl.cc
index e4a133261579296415cda12d4a304d653473c79c..a199e81df506098c699deb1f217ef74a69d760e9 100644
--- a/media/mojo/services/mojo_renderer_impl.cc
+++ b/media/mojo/services/mojo_renderer_impl.cc
@@ -105,7 +105,7 @@ void MojoRendererImpl::StartPlayingFrom(base::TimeDelta time) {
   remote_media_renderer_->StartPlayingFrom(time.InMicroseconds());
 }
 
-void MojoRendererImpl::SetPlaybackRate(float playback_rate) {
+void MojoRendererImpl::SetPlaybackRate(double playback_rate) {
   DVLOG(2) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
   remote_media_renderer_->SetPlaybackRate(playback_rate);