Make simulcast screenshare default-on

Bug: chromium:690537
Change-Id: I7380f5e7b3faa20ba60bebee8b8b4d74db885faf
Reviewed-on: https://webrtc-review.googlesource.com/c/112381
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25840}
diff --git a/media/engine/webrtcvideoengine_unittest.cc b/media/engine/webrtcvideoengine_unittest.cc
index ab04fa6..543fa3a 100644
--- a/media/engine/webrtcvideoengine_unittest.cc
+++ b/media/engine/webrtcvideoengine_unittest.cc
@@ -6976,21 +6976,19 @@
 
 TEST_F(WebRtcVideoChannelSimulcastTest,
        SetSendCodecsForConferenceModeScreenshare) {
+  webrtc::test::ScopedFieldTrials field_trials(
+      "WebRTC-SimulcastScreenshare/Disabled/");
   VerifySimulcastSettings(cricket::VideoCodec("VP8"), 1280, 720, 3, 1, true,
                           true);
 }
 
 TEST_F(WebRtcVideoChannelSimulcastTest, SetSendCodecsForSimulcastScreenshare) {
-  webrtc::test::ScopedFieldTrials override_field_trials_(
-      "WebRTC-SimulcastScreenshare/Enabled/");
   VerifySimulcastSettings(cricket::VideoCodec("VP8"), 1280, 720, 3, 2, true,
                           true);
 }
 
 TEST_F(WebRtcVideoChannelSimulcastTest,
        NoSimulcastScreenshareWithoutConference) {
-  webrtc::test::ScopedFieldTrials override_field_trials_(
-      "WebRTC-SimulcastScreenshare/Enabled/");
   VerifySimulcastSettings(cricket::VideoCodec("VP8"), 1280, 720, 3, 1, true,
                           false);
 }