Replace RTC_DCHECK(false) with RTC_NOTREACHED().

webrtc/p2p/base/dtlstransportchannel.cc

Index: webrtc/p2p/base/dtlstransportchannel.cc
diff --git a/webrtc/p2p/base/dtlstransportchannel.cc b/webrtc/p2p/base/dtlstransportchannel.cc
index 8aea40c79a8251bca72fc8d4a727a45b2e676cfa..02f3d594b53680e66b52bfa58ed900c1b2c09868 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -633,7 +633,7 @@ void DtlsTransportChannelWrapper::MaybeStartDtls() {
       // packets in this state, the incoming queue must be empty. We
       // ignore write errors, thus any errors must be because of
       // configuration and therefore are our fault.
-      RTC_DCHECK(false) << "StartSSL failed.";
+      RTC_NOTREACHED() << "StartSSL failed.";
       LOG_J(LS_ERROR, this) << "Couldn't start DTLS handshake";
       set_dtls_state(DTLS_TRANSPORT_FAILED);
       return;