Add flag in device enumeration request to control label clearing and don't clear for pepper.

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 7854a8d6574bbd60bfe53e5d92357ba4945e297d..32ac1de61d35801680b8e5c8fc55d07b2c5ee70d 100644
--- a/content/renderer/media/mock_media_stream_dispatcher.cc
+++ b/content/renderer/media/mock_media_stream_dispatcher.cc
@@ -59,7 +59,8 @@ void MockMediaStreamDispatcher::EnumerateDevices(
     int request_id,
     const base::WeakPtr<MediaStreamDispatcherEventHandler>& event_handler,
     MediaStreamType type,
-    const GURL& security_origin) {
+    const GURL& security_origin,
+    bool hide_labels_if_no_access) {
   if (type == MEDIA_DEVICE_AUDIO_CAPTURE) {
     audio_input_request_id_ = request_id;
     audio_input_array_.clear();