Revert "Reland "Enable simulcast screenshare by default""

This reverts commit 89b2963.

Reason for revert: Make experiment default off to not mess up data in re-launch.

Original change's description:
> Reland "Enable simulcast screenshare by default"
>
> This is a reland of d43c692 after fixes
> to failing chromium tests. No change to the original CL were done.
> Original CL reviewed on: https://webrtc-review.googlesource.com/87560
>
> [email protected]
>
> Bug: chromium:690537
> Change-Id: I6b59ffc90d789aff21c7e52b118d3dfbe756c8a9
> Reviewed-on: https://webrtc-review.googlesource.com/89081
> Reviewed-by: Ilya Nikolaevskiy <[email protected]>
> Commit-Queue: Ilya Nikolaevskiy <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#24013}

[email protected],[email protected],[email protected]

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: chromium:690537, b:116052898
Change-Id: I429677de5547ce3a7badfb4414231ff9589e7414
Reviewed-on: https://webrtc-review.googlesource.com/101560
Reviewed-by: Ilya Nikolaevskiy <[email protected]>
Commit-Queue: Erik Språng <[email protected]>
Cr-Commit-Position: refs/heads/master@{#24798}

Author: Erik Språng

media/engine/simulcast.cc

@@ -382,7 +382,7 @@ std::vector<webrtc::VideoStream> GetScreenshareLayers(
 }
 
 bool ScreenshareSimulcastFieldTrialEnabled() {
-  return !webrtc::field_trial::IsDisabled(kSimulcastScreenshareFieldTrialName);
+  return webrtc::field_trial::IsEnabled(kSimulcastScreenshareFieldTrialName);
 }
 
 }  // namespace cricket

media/engine/simulcast_unittest.cc

@@ -165,8 +165,6 @@ TEST(SimulcastTest, GetConfigWithNormalizedResolution) {
 }
 
 TEST(SimulcastTest, GetConfigForScreenshare) {
-  test::ScopedFieldTrials field_trials("WebRTC-SimulcastScreenshare/Disabled/");
-
   const size_t kMaxLayers = 3;
   std::vector<VideoStream> streams = cricket::GetSimulcastConfig(
       kMaxLayers, 1400, 800, kMaxBitrateBps, kBitratePriority, kQpMax, kMaxFps,
@@ -186,6 +184,8 @@ TEST(SimulcastTest, GetConfigForScreenshare) {
 }
 
 TEST(SimulcastTest, GetConfigForScreenshareSimulcast) {
+  test::ScopedFieldTrials field_trials("WebRTC-SimulcastScreenshare/Enabled/");
+
   const size_t kMaxLayers = 3;
   std::vector<VideoStream> streams = cricket::GetSimulcastConfig(
       kMaxLayers, 1400, 800, kMaxBitrateBps, kBitratePriority, kQpMax, kMaxFps,

media/engine/webrtcvideoengine_unittest.cc

@@ -6670,32 +6670,28 @@ TEST_F(WebRtcVideoChannelSimulcastTest, SetSendCodecsWithOddSizeInSimulcast) {
                           true);
 }
 
-// TODO(ilnik): Remove this test once Simulcast Screenshare is launched.
 TEST_F(WebRtcVideoChannelSimulcastTest, SetSendCodecsForScreenshare) {
-  webrtc::test::ScopedFieldTrials override_field_trials_(
-      "WebRTC-SimulcastScreenshare/Disabled/");
-
   VerifySimulcastSettings(cricket::VideoCodec("VP8"), 1280, 720, 3, 1, true,
                           false);
 }
 
-// TODO(ilnik): Remove this test once Simulcast Screenshare is launched.
 TEST_F(WebRtcVideoChannelSimulcastTest,
        SetSendCodecsForConferenceModeScreenshare) {
-  webrtc::test::ScopedFieldTrials override_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);
 }

video/full_stack_tests.cc

@@ -46,8 +46,8 @@ namespace webrtc {
 
 namespace {
 static const int kFullStackTestDurationSecs = 45;
-const char kNotScreenshareSimulcastExperiment[] =
-    "WebRTC-SimulcastScreenshare/Disabled/";
+const char kScreenshareSimulcastExperiment[] =
+    "WebRTC-SimulcastScreenshare/Enabled/";
 const char kPacerPushBackExperiment[] =
     "WebRTC-PacerPushbackExperiment/Enabled/";
 
@@ -597,7 +597,6 @@ TEST(FullStackTest, ConferenceMotionHd2000kbps100msLimitedQueueVP9) {
 #endif
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
@@ -612,6 +611,7 @@ TEST(FullStackTest, ScreenshareSlidesVP8_2TL) {
 
 TEST(FullStackTest, ScreenshareSlidesVP8_3TL_Simulcast) {
   auto fixture = CreateVideoQualityTestFixture();
+  test::ScopedFieldTrials field_trial(kScreenshareSimulcastExperiment);
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
   screenshare.screenshare[0] = {true, false, 10};
@@ -639,8 +639,6 @@ TEST(FullStackTest, ScreenshareSlidesVP8_3TL_Simulcast) {
 }
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL_Scroll) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
-
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging config;
   config.call.send_side_bwe = true;
@@ -654,8 +652,6 @@ TEST(FullStackTest, ScreenshareSlidesVP8_2TL_Scroll) {
 }
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL_LossyNet) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
-
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
@@ -672,8 +668,6 @@ TEST(FullStackTest, ScreenshareSlidesVP8_2TL_LossyNet) {
 }
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL_VeryLossyNet) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
-
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
@@ -690,8 +684,6 @@ TEST(FullStackTest, ScreenshareSlidesVP8_2TL_VeryLossyNet) {
 }
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL_LossyNetRestrictedQueue) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
-
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
@@ -709,8 +701,6 @@ TEST(FullStackTest, ScreenshareSlidesVP8_2TL_LossyNetRestrictedQueue) {
 }
 
 TEST(FullStackTest, ScreenshareSlidesVP8_2TL_ModeratelyRestricted) {
-  test::ScopedFieldTrials field_trial(kNotScreenshareSimulcastExperiment);
-
   auto fixture = CreateVideoQualityTestFixture();
   ParamsWithLogging screenshare;
   screenshare.call.send_side_bwe = true;
@@ -1070,7 +1060,8 @@ class DualStreamsTest : public ::testing::TestWithParam<int> {};
 TEST_P(DualStreamsTest,
        ModeratelyRestricted_SlidesVp8_3TL_Simulcast_Video_Simulcast_High) {
   test::ScopedFieldTrials field_trial(
-      AppendFieldTrials(std::string(kPacerPushBackExperiment)));
+      AppendFieldTrials(std::string(kPacerPushBackExperiment) +
+                        std::string(kScreenshareSimulcastExperiment)));
   const int first_stream = GetParam();
   ParamsWithLogging dual_streams;