Revert of Add experimental simulcast screen content mode (patchset #5 id:80001 of https://codereview.webrtc.org/2636443002/ )

Reason for revert:
Breaks chromium.

Original issue's description:
> Add experimental simulcast screen content mode
>
> BUG=webrtc:4172
>
> Review-Url: https://codereview.webrtc.org/2636443002
> Cr-Commit-Position: refs/heads/master@{#16135}
> Committed: https://chromium.googlesource.com/external/webrtc/+/a28e971e3bc8a06f366f0ef82cc7168b05a83b59

TBR=perkj@webrtc.org,asapersson@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:4172

Review-Url: https://codereview.webrtc.org/2643763002
Cr-Commit-Position: refs/heads/master@{#16145}
diff --git a/webrtc/modules/video_coding/video_codec_initializer.cc b/webrtc/modules/video_coding/video_codec_initializer.cc
index 9d15952..dbdede0 100644
--- a/webrtc/modules/video_coding/video_codec_initializer.cc
+++ b/webrtc/modules/video_coding/video_codec_initializer.cc
@@ -38,8 +38,8 @@
     case kVideoCodecVP8: {
       if (!codec->VP8()->tl_factory) {
         if (codec->mode == kScreensharing &&
-            codec->numberOfSimulcastStreams >= 1 &&
-            codec->VP8()->numberOfTemporalLayers >= 1) {
+            codec->numberOfSimulcastStreams == 1 &&
+            codec->VP8()->numberOfTemporalLayers == 2) {
           // Conference mode temporal layering for screen content.
           tl_factory.reset(new ScreenshareTemporalLayersFactory());
         } else {