Implement stable rate support in SimulcastRateAllocator

Bug: webrtc:10126
Change-Id: I2ea8d27b0bd6f7ffd1ebbba451bd1ce1f2eee3d9
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/151121
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29097}
diff --git a/modules/video_coding/BUILD.gn b/modules/video_coding/BUILD.gn
index eafbd39..dc9f018 100644
--- a/modules/video_coding/BUILD.gn
+++ b/modules/video_coding/BUILD.gn
@@ -264,6 +264,7 @@
     "../../rtc_base/experiments:quality_scaler_settings",
     "../../rtc_base/experiments:quality_scaling_experiment",
     "../../rtc_base/experiments:rate_control_settings",
+    "../../rtc_base/experiments:stable_target_rate_experiment",
     "../../rtc_base/synchronization:sequence_checker",
     "../../rtc_base/system:arch",
     "../../rtc_base/system:file_wrapper",