Propagate audible state from player to the containing tab

content/browser/android/audio_monitor_android.cc

Index: content/browser/android/audio_monitor_android.cc
diff --git a/content/browser/android/audio_monitor_android.cc b/content/browser/android/audio_monitor_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5e71876188be9787a51e4d51e23c3e2b8291e44b
--- /dev/null
+++ b/content/browser/android/audio_monitor_android.cc
@@ -0,0 +1,53 @@
+// Copyright (c) 2015 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/android/audio_monitor_android.h"
+
+#include <climits>
+#include "content/public/browser/web_contents.h"
+
+namespace content {
+
+AudioMonitorAndroid::AudioMonitorAndroid(WebContents* web_contents)
+    : web_contents_(web_contents),
+      is_audible_(false) {
+}
+
+AudioMonitorAndroid::~AudioMonitorAndroid() {}
+
+void AudioMonitorAndroid::OnAudibleStateChanged(RenderFrameHost* rfh,
+                                                int player_id,
+                                                bool is_audible) {
+  audio_status_map_[Key(rfh, player_id)] = is_audible;
+  UpdateStatusAndNotify();
+}
+
+void AudioMonitorAndroid::RemovePlayer(RenderFrameHost* rfh, int player_id) {
+  audio_status_map_.erase(Key(rfh, player_id));
+  UpdateStatusAndNotify();
+}
+
+void AudioMonitorAndroid::RenderFrameDeleted(RenderFrameHost* rfh) {
+  StatusMap::iterator begin = audio_status_map_.lower_bound(Key(rfh, 0));
+  StatusMap::iterator end = audio_status_map_.upper_bound(Key(rfh, INT_MAX));
+  audio_status_map_.erase(begin, end);
+  UpdateStatusAndNotify();
+}
+
+void AudioMonitorAndroid::UpdateStatusAndNotify() {
+  bool is_audible = false;
+  for (const auto& player_status : audio_status_map_) {
+    if (player_status.second) {
+      is_audible = true;
+      break; // at least one player is making noise
+    }
+  }
+
+  if (is_audible_ != is_audible) {
+    is_audible_ = is_audible;
+    web_contents_->NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);

[Ted C, 2015/02/07 00:07:15]

Is this the navigation state that chrome uses to up date it's speaker icon from
the tab strip (i.e. from TabStripModel::UpdateWebContentsStateAt ->
BrowserTabStripController::TabChangedAt)?

[Tima Vaisburd, 2015/02/07 03:00:23]

Yes, on desktop the AudioStreamMonitor makes the same call, see
https://cs.corp.google.com/#clankium/src/content/browser/media/audio_stream_m...

+  }
+}
+
+} // namespace content