Revert of Use mojo support for Blink devicechange event.

content/renderer/media/user_media_client_impl.cc

Index: content/renderer/media/user_media_client_impl.cc
diff --git a/content/renderer/media/user_media_client_impl.cc b/content/renderer/media/user_media_client_impl.cc
index c3fdcac03d9a95739e8dc2772a858074b57b66f2..29a9819980bc895ab2c2134a6ef8bf686e400dab 100644
--- a/content/renderer/media/user_media_client_impl.cc
+++ b/content/renderer/media/user_media_client_impl.cc
@@ -287,26 +287,13 @@
     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()) {
-    event_dispatcher->UnsubscribeDeviceChangeNotifications(
-        device_change_subscription_ids_);
-    device_change_subscription_ids_.clear();
+    media_stream_dispatcher_->CancelDeviceChangeNotifications(
+        weak_factory_.GetWeakPtr());
   } else {
-    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()));
+    url::Origin origin = observer.getSecurityOrigin();
+    media_stream_dispatcher_->SubscribeToDeviceChangeNotifications(
+        weak_factory_.GetWeakPtr(), origin);
   }
 }
 
@@ -612,8 +599,6 @@
   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) {
@@ -635,15 +620,8 @@
   NOTIMPLEMENTED();
 }
 
-// TODO(guidou): Remove once this method is removed from the
-// MediaStreamDispatcherEventHandler interface. http://648183.
 void UserMediaClientImpl::OnDevicesChanged() {
-  NOTREACHED();
-}
-
-void UserMediaClientImpl::DevicesChanged(
-    MediaDeviceType type,
-    const MediaDeviceInfoArray& device_infos) {
+  DVLOG(1) << "UserMediaClientImpl::OnDevicesChanged()";
   if (!media_device_change_observer_.isNull())
     media_device_change_observer_.didChangeMediaDevices();
 }