[scheduler] Teach scheduler about audio state

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 1237 matching lines @@
       audio_muter_.reset(new WebContentsAudioMuter(this));
     audio_muter_->StartMuting();
   } else {
     DCHECK(audio_muter_);
     audio_muter_->StopMuting();
   }
 
   for (auto& observer : observers_)
     observer.DidUpdateAudioMutingState(mute);
 
-  // Notification for UI updates in response to the changed muting state.
-  NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);
+  OnAudioStateChanged(!mute && audio_stream_monitor_.IsCurrentlyAudible());
 }
 
 bool WebContentsImpl::IsConnectedToBluetoothDevice() const {
   return bluetooth_connected_device_count_ > 0;
 }
 
 bool WebContentsImpl::IsCrashed() const {
   return (crashed_status_ == base::TERMINATION_STATUS_PROCESS_CRASHED ||
           crashed_status_ == base::TERMINATION_STATUS_ABNORMAL_TERMINATION ||
           crashed_status_ == base::TERMINATION_STATUS_PROCESS_WAS_KILLED ||
@@ skipping 39 matching lines @@
     media_web_contents_observer_->MaybeUpdateAudibleState();
   }
 
   if (delegate_)
     delegate_->NavigationStateChanged(this, changed_flags);
 
   if (GetOuterWebContents())
     GetOuterWebContents()->NotifyNavigationStateChanged(changed_flags);
 }
 
+void WebContentsImpl::OnAudioStateChanged(bool is_audio_playing) {
+  SendPageMessage(
+      new PageMsg_AudioStateChanged(MSG_ROUTING_NONE, is_audio_playing));
+
+  // Notification for UI updates in response to the changed muting state.

[miu, 2016/11/15 22:04:04]

nit: The wording here could be confusing. There are two concepts in the UI: 1)
Whether an audio stream is audible (i.e., not silent); and 2) Whether an audio
stream has been muted (i.e., user or extension API controls were used to mute
audio stream). Can you fix this?

[altimin, 2016/11/16 12:22:32]

Addressed in crrev.com/2496173003

+  NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);
+}
+
 base::TimeTicks WebContentsImpl::GetLastActiveTime() const {
   return last_active_time_;
 }
 
 void WebContentsImpl::SetLastActiveTime(base::TimeTicks last_active_time) {
   last_active_time_ = last_active_time;
 }
 
 void WebContentsImpl::WasShown() {
   controller_.SetActive(true);
@@ skipping 3858 matching lines @@
   dialog_manager_ = dialog_manager;
 }
 
 void WebContentsImpl::RemoveBindingSet(const std::string& interface_name) {
   auto it = binding_sets_.find(interface_name);
   if (it != binding_sets_.end())
     binding_sets_.erase(it);
 }
 
 }  // namespace content