Reland of Use mojo support for Blink devicechange event.

content/renderer/media/user_media_client_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/renderer/media/user_media_client_impl.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 269 matching lines @@
       true /* audio input */, true /* video input */, true /* audio output */,
       security_origin,
       base::Bind(&UserMediaClientImpl::FinalizeEnumerateDevices,
                  weak_factory_.GetWeakPtr(), media_devices_request));
 }
 
 void UserMediaClientImpl::setMediaDeviceChangeObserver(
     const blink::WebMediaDeviceChangeObserver& observer) {
   media_device_change_observer_ = observer;
 
+  // Do nothing if setting a valid observer while already subscribed or setting
+  // no observer while unsubscribed.
+  if (media_device_change_observer_.isNull() ==
+      device_change_subscription_ids_.empty())
+    return;
+
+  base::WeakPtr<MediaDevicesEventDispatcher> event_dispatcher =
+      MediaDevicesEventDispatcher::GetForRenderFrame(render_frame());
   if (media_device_change_observer_.isNull()) {
-    media_stream_dispatcher_->CancelDeviceChangeNotifications(
-        weak_factory_.GetWeakPtr());
+    event_dispatcher->UnsubscribeDeviceChangeNotifications(
+        device_change_subscription_ids_);
+    device_change_subscription_ids_.clear();
   } else {
-    url::Origin origin = observer.getSecurityOrigin();
-    media_stream_dispatcher_->SubscribeToDeviceChangeNotifications(
-        weak_factory_.GetWeakPtr(), origin);
+    DCHECK(device_change_subscription_ids_.empty());
+    url::Origin security_origin =
+        media_device_change_observer_.getSecurityOrigin();
+    device_change_subscription_ids_ =
+        event_dispatcher->SubscribeDeviceChangeNotifications(
+            security_origin, base::Bind(&UserMediaClientImpl::DevicesChanged,
+                                        weak_factory_.GetWeakPtr()));
   }
 }
 
 // Callback from MediaStreamDispatcher.
 // The requested stream have been generated by the MediaStreamDispatcher.
 void UserMediaClientImpl::OnStreamGenerated(
     int request_id,
     const std::string& label,
     const StreamDeviceInfoArray& audio_array,
     const StreamDeviceInfoArray& video_array) {
@@ skipping 285 matching lines @@
     for (auto& web_track : tracks) {
       MediaStreamTrack* track = MediaStreamTrack::GetTrack(web_track);
       if (track)
         track->Stop();
     }
   }
 
   DeleteUserMediaRequestInfo(request);
 }
 
+// TODO(guidou): Remove once this method is removed from the
+// MediaStreamDispatcherEventHandler interface. http://648183.
 void UserMediaClientImpl::OnDevicesEnumerated(
     int request_id,
     const StreamDeviceInfoArray& device_array) {
   NOTREACHED();
 }
 
 void UserMediaClientImpl::OnDeviceOpened(
     int request_id,
     const std::string& label,
     const StreamDeviceInfo& video_device) {
   DVLOG(1) << "UserMediaClientImpl::OnDeviceOpened("
            << request_id << ", " << label << ")";
   NOTIMPLEMENTED();
 }
 
 void UserMediaClientImpl::OnDeviceOpenFailed(int request_id) {
   DVLOG(1) << "UserMediaClientImpl::VideoDeviceOpenFailed("
            << request_id << ")";
   NOTIMPLEMENTED();
 }
 
+// TODO(guidou): Remove once this method is removed from the
+// MediaStreamDispatcherEventHandler interface. http://648183.
 void UserMediaClientImpl::OnDevicesChanged() {
-  DVLOG(1) << "UserMediaClientImpl::OnDevicesChanged()";
+  NOTREACHED();
+}
+
+void UserMediaClientImpl::DevicesChanged(
+    MediaDeviceType type,
+    const MediaDeviceInfoArray& device_infos) {
   if (!media_device_change_observer_.isNull())
     media_device_change_observer_.didChangeMediaDevices();
 }
 
 void UserMediaClientImpl::GetUserMediaRequestSucceeded(
     const blink::WebMediaStream& stream,
     blink::WebUserMediaRequest request_info) {
   // Completing the getUserMedia request can lead to that the RenderFrame and
   // the UserMediaClientImpl is destroyed if the JavaScript code request the
   // frame to be destroyed within the scope of the callback. Therefore,
@@ skipping 335 matching lines @@
 
 bool UserMediaClientImpl::UserMediaRequestInfo::HasPendingSources() const {
   return !sources_waiting_for_callback_.empty();
 }
 
 void UserMediaClientImpl::OnDestruct() {
   delete this;
 }
 
 }  // namespace content