Revert "Implement H264 simulcast support and generalize SimulcastEncoderAdapter use for H264 & VP8."

This reverts commit 07efe436c9002e139845f62486e3ee4e29f0d85b.

Reason for revert: Breaks downstream project.

cricket::GetSimulcastConfig method signature has been updated.
I think you can get away with a default value for temporal_layers_supported (and then you can remove it after a few days when projects will be updated).


Original change's description:
> Implement H264 simulcast support and generalize SimulcastEncoderAdapter use for H264 & VP8.
> 
> * Move SimulcastEncoderAdapter out under modules/video_coding
> * Move SimulcastRateAllocator back out to modules/video_coding/utility
> * Move TemporalLayers and ScreenshareLayers to modules/video_coding/utility
> * Move any VP8 specific code - such as temporal layer bitrate budgeting -
>   under codec type dependent conditionals.
> * Plumb the simulcast index for H264 in the codec specific and RTP format data structures.
> 
> Bug: webrtc:5840
> Change-Id: Ieced8a00e38f273c1a6cfd0f5431a87d07b8f44e
> Reviewed-on: https://webrtc-review.googlesource.com/64100
> Commit-Queue: Harald Alvestrand <hta@webrtc.org>
> Reviewed-by: Stefan Holmer <stefan@webrtc.org>
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#23705}

TBR=sprang@webrtc.org,stefan@webrtc.org,mflodman@webrtc.org,hta@webrtc.org,sergio.garcia.murillo@gmail.com,titovartem@webrtc.org,agouaillard@gmail.com

Change-Id: Ic9d3b1eeaf195bb5ec2063954421f5e77866d663
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:5840
Reviewed-on: https://webrtc-review.googlesource.com/84760
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23710}
diff --git a/media/engine/webrtcvideoengine_unittest.cc b/media/engine/webrtcvideoengine_unittest.cc
index 039de76..2b048fc 100644
--- a/media/engine/webrtcvideoengine_unittest.cc
+++ b/media/engine/webrtcvideoengine_unittest.cc
@@ -770,9 +770,7 @@
   ASSERT_EQ(0u, encoder_factory_->encoders().size());
 }
 
-TEST_F(WebRtcVideoEngineTest, SimulcastEnabledForH264BehindFieldTrial) {
-  webrtc::test::ScopedFieldTrials override_field_trials_(
-      "WebRTC-H264Simulcast/Enabled/");
+TEST_F(WebRtcVideoEngineTest, SimulcastDisabledForH264) {
   encoder_factory_->AddSupportedVideoCodecType("H264");
 
   std::unique_ptr<VideoMediaChannel> channel(
@@ -798,7 +796,7 @@
   FakeWebRtcVideoEncoder* encoder = encoder_factory_->encoders()[0];
   ASSERT_TRUE(encoder_factory_->encoders()[0]->WaitForInitEncode());
   EXPECT_EQ(webrtc::kVideoCodecH264, encoder->GetCodecSettings().codecType);
-  EXPECT_LT(1u, encoder->GetCodecSettings().numberOfSimulcastStreams);
+  EXPECT_EQ(1u, encoder->GetCodecSettings().numberOfSimulcastStreams);
   EXPECT_TRUE(channel->SetVideoSend(ssrcs[0], nullptr, nullptr));
 }
 
@@ -6186,7 +6184,7 @@
       expected_streams = GetSimulcastConfig(
           num_configured_streams, capture_width, capture_height, 0,
           webrtc::kDefaultBitratePriority, kDefaultQpMax,
-          kDefaultVideoMaxFramerate, screenshare, true);
+          kDefaultVideoMaxFramerate, screenshare);
       if (screenshare) {
         for (const webrtc::VideoStream& stream : expected_streams) {
           // Never scale screen content.