Refactor MediaStreamManager to never output real device id. It now always output sourceId in the fo…

content/renderer/media/mock_media_stream_dispatcher.cc

Index: content/renderer/media/mock_media_stream_dispatcher.cc
diff --git a/content/renderer/media/mock_media_stream_dispatcher.cc b/content/renderer/media/mock_media_stream_dispatcher.cc
index a1b9527959fe6c7baac2de3d64ea126eae0f8fb6..d9a83b0f17da9fc327aeeb3534d4d9cee759b3e8 100644
--- a/content/renderer/media/mock_media_stream_dispatcher.cc
+++ b/content/renderer/media/mock_media_stream_dispatcher.cc
@@ -28,13 +28,14 @@ void MockMediaStreamDispatcher::GenerateStream(
     const GURL& url) {
   request_id_ = request_id;
 
-  stream_label_ = base::StringPrintf("%s%d","local_stream",request_id);
+  stream_label_ = base::StringPrintf("%s%d", "local_stream", request_id);
   audio_array_.clear();
   video_array_.clear();
 
   if (IsAudioMediaType(components.audio_type)) {
     StreamDeviceInfo audio;
-    audio.device.id = "audio_device_id";
+    audio.device.id = base::StringPrintf("%s%d", "audio_device_id",
+                                         session_id_);
     audio.device.name = "microphone";
     audio.device.type = components.audio_type;
     audio.session_id = session_id_;
@@ -42,7 +43,8 @@ void MockMediaStreamDispatcher::GenerateStream(
   }
   if (IsVideoMediaType(components.video_type)) {
     StreamDeviceInfo video;
-    video.device.id = "video_device_id";
+    video.device.id = base::StringPrintf("%s%d", "video_device_id",
+                                         session_id_);
     video.device.name = "usb video camera";
     video.device.type = components.video_type;
     video.session_id = session_id_;