sdp: cleanup WebRTC-PreventSsrcGroupsWithUnexpectedSize killswitch

the rollout has happened a while ago with no issues requiring the use
of the killswitch

BUG=chromium:40066610

Change-Id: I2c8148976a1da219ebbfbe6908224b6384348194
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/348823
Commit-Queue: Philipp Hancke <phancke@meta.com>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Emil Lundmark <lndmrk@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42164}
diff --git a/experiments/field_trials.py b/experiments/field_trials.py
index eb99b14..2ffcbeb 100755
--- a/experiments/field_trials.py
+++ b/experiments/field_trials.py
@@ -105,9 +105,6 @@
     FieldTrial('WebRTC-PermuteTlsClientHello',
                'webrtc:15467',
                date(2024, 7, 1)),
-    FieldTrial('WebRTC-PreventSsrcGroupsWithUnexpectedSize',
-               'chromium:1459124',
-               date(2024, 4, 1)),
     FieldTrial('WebRTC-ReceiveBufferSize',
                'webrtc:15585',
                date(2024, 4, 1)),
diff --git a/pc/sdp_offer_answer.cc b/pc/sdp_offer_answer.cc
index 95d5497..68d89e4 100644
--- a/pc/sdp_offer_answer.cc
+++ b/pc/sdp_offer_answer.cc
@@ -3576,10 +3576,9 @@
     return error;
   }
 
-  // TODO(crbug.com/1459124): remove killswitch after rollout.
+  // Validate the SSRC groups.
   error = ValidateSsrcGroups(*sdesc->description());
-  if (!error.ok() &&
-      !pc_->trials().IsDisabled("WebRTC-PreventSsrcGroupsWithUnexpectedSize")) {
+  if (!error.ok()) {
     return error;
   }