[scheduler] Teach scheduler about audio state

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index 26a2c454d5a5cd2f55da9ced967fd1534bc17ab9..86eafc934c119326e5188daeeace812b8cda8a9f 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -780,6 +780,7 @@ bool ChildThreadImpl::OnMessageReceived(const IPC::Message& msg) {
                         OnProfilingPhaseCompleted)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_SetProcessBackgrounded,
                         OnProcessBackgrounded)
+    IPC_MESSAGE_HANDLER(ChildProcessMsg_SetAudioPlaying, OnAudioStateChanged)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_PurgeAndSuspend,
                         OnProcessPurgeAndSuspend)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -811,6 +812,8 @@ void ChildThreadImpl::OnProcessBackgrounded(bool backgrounded) {
   base::MessageLoop::current()->SetTimerSlack(timer_slack);
 }
 
+void ChildThreadImpl::OnAudioStateChanged(bool has_active_audio) {}
+
 void ChildThreadImpl::OnProcessPurgeAndSuspend() {
 }