Disable dcheck on linux

Bug: webrtc:11490
Change-Id: I731daa08378e861aeb51da3b819e3c472a9cad9b
No-Try: true
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172937
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31012}

video/receive_statistics_proxy.cc

@@ -652,7 +652,10 @@ void ReceiveStatisticsProxy::UpdateDecodeTimeHistograms(
 absl::optional<int64_t>
 ReceiveStatisticsProxy::GetCurrentEstimatedPlayoutNtpTimestampMs(
     int64_t now_ms) const {
+  // TODO(webrtc:11489): Update downstream tests.
+#if !defined(WEBRTC_LINUX)
   RTC_DCHECK_RUN_ON(&main_thread_);
+#endif
   if (!last_estimated_playout_ntp_timestamp_ms_ ||
       !last_estimated_playout_time_ms_) {
     return absl::nullopt;