Bug 1653219 - Enumerate browser tabs before entire screen; r=ng

A lot of tests assume that the screen will be the last thing enumerated.
It is also the "scariest" option, so having it last makes sense.

Differential Revision: https://phabricator.services.mozilla.com/D84593

dom/media/webrtc/MediaEngineWebRTC.cpp

@@ -261,8 +261,8 @@ void MediaEngineWebRTC::EnumerateDevices(
         // window and fullscreen into a single list of choices. The other values
         // are still useful for testing.
         EnumerateVideoDevices(aWindowId, camera::WinEngine, aDevices);
-        EnumerateVideoDevices(aWindowId, camera::ScreenEngine, aDevices);
         EnumerateVideoDevices(aWindowId, camera::BrowserEngine, aDevices);
+        EnumerateVideoDevices(aWindowId, camera::ScreenEngine, aDevices);
         break;
       case dom::MediaSourceEnum::Screen:
         EnumerateVideoDevices(aWindowId, camera::ScreenEngine, aDevices);