Add RTC_ prefix to (D)CHECKs and related macros.

webrtc/base/asyncinvoker.cc

Index: webrtc/base/asyncinvoker.cc
diff --git a/webrtc/base/asyncinvoker.cc b/webrtc/base/asyncinvoker.cc
index ee53e04184cf06cda4a674bcfec9bdf6e4a06666..563ccb7afd48968e39c935f9e3f1b525309a444b 100644
--- a/webrtc/base/asyncinvoker.cc
+++ b/webrtc/base/asyncinvoker.cc
@@ -96,7 +96,7 @@ bool GuardedAsyncInvoker::Flush(uint32 id) {
 void GuardedAsyncInvoker::ThreadDestroyed() {
   rtc::CritScope cs(&crit_);
   // We should never get more than one notification about the thread dying.
-  DCHECK(thread_ != nullptr);
+  RTC_DCHECK(thread_ != nullptr);
   thread_ = nullptr;
 }