Adding possibility to bypass MediaStream UI to be able to rununit tests on server.

content/browser/renderer_host/media/media_stream_device_settings.h

Index: content/browser/renderer_host/media/media_stream_device_settings.h
===================================================================
--- content/browser/renderer_host/media/media_stream_device_settings.h	(revision 91703)
+++ content/browser/renderer_host/media/media_stream_device_settings.h	(working copy)
@@ -58,6 +58,11 @@
   void AvailableDevices(const std::string& label, MediaStreamType stream_type,
                         const StreamDeviceInfoArray& devices);
 
+  // Used for testing only. This function is called to use faked UI, which is
+  // needed for server based tests. The first non-opened device(s) will be
+  // picked.
+  void UseFakeUI();
+
  private:
   struct SettingsRequest;
 
@@ -66,6 +71,8 @@
   typedef std::map<std::string, SettingsRequest*> SettingsRequests;
   SettingsRequests requests_;
 
+  bool use_fake_ui_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaStreamDeviceSettings);
 };