Cast: Enable high-resolution timers while casting.

chrome/renderer/media/cast_session_delegate.cc

Index: chrome/renderer/media/cast_session_delegate.cc
diff --git a/chrome/renderer/media/cast_session_delegate.cc b/chrome/renderer/media/cast_session_delegate.cc
index 2bd43161d9ad70b6d057c5e522b735c1cd1c79a4..7e03b53f82bd45bd288c7c9acdbb14f66c98cd6a 100644
--- a/chrome/renderer/media/cast_session_delegate.cc
+++ b/chrome/renderer/media/cast_session_delegate.cc
@@ -37,10 +37,18 @@ CastSessionDelegateBase::CastSessionDelegateBase()
           content::RenderThread::Get()->GetIOMessageLoopProxy()),
       weak_factory_(this) {
   DCHECK(io_task_runner_.get());
+#if defined(OS_WIN)
+  if (!base::Time::ActivateHighResolutionTimer(true)) {

[miu, 2015/05/07 20:04:34]

nit: This led me to think this only provides better time precision on the "old
machines."  But, as we discussed, it also affects the threading timeslices.  Can
you add a quick comment to that effect here?

+    LOG(WARNING) << "Failed to activate high resolution timers for cast.";
+  }
+#endif
 }
 
 CastSessionDelegateBase::~CastSessionDelegateBase() {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
+#if defined(OS_WIN)
+  base::Time::ActivateHighResolutionTimer(false);
+#endif
 }
 
 void CastSessionDelegateBase::StartUDP(