Revert "Allow remote fingerprint update during a call"

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 fce7469cf641424715e48bd343500f33f0c165ab..fff24f30b81617e39475f5e804902f6782d979c2 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -199,8 +199,6 @@ bool DtlsTransportChannelWrapper::SetRemoteFingerprint(
     size_t digest_len) {
   rtc::Buffer remote_fingerprint_value(digest, digest_len);
 
-  // Once we have the local certificate, the same remote fingerprint can be set
-  // multiple times.
   if (dtls_active_ && remote_fingerprint_value_ == remote_fingerprint_value &&
       !digest_alg.empty()) {
     // This may happen during renegotiation.
@@ -208,36 +206,28 @@ bool DtlsTransportChannelWrapper::SetRemoteFingerprint(
     return true;
   }
 
-  // If the other side doesn't support DTLS, turn off |dtls_active_|.
+  // Allow SetRemoteFingerprint with a NULL digest even if SetLocalCertificate
+  // hasn't been called.
+  if (dtls_ || (!dtls_active_ && !digest_alg.empty())) {
+    LOG_J(LS_ERROR, this) << "Can't set DTLS remote settings in this state.";
+    return false;
+  }
+
   if (digest_alg.empty()) {
-    RTC_DCHECK(!digest_len);
     LOG_J(LS_INFO, this) << "Other side didn't support DTLS.";
     dtls_active_ = false;
     return true;
   }
 
-  // Otherwise, we must have a local certificate before setting remote
-  // fingerprint.
-  if (!dtls_active_) {
-    LOG_J(LS_ERROR, this) << "Can't set DTLS remote settings in this state.";
-    return false;
-  }
-
   // At this point we know we are doing DTLS
   remote_fingerprint_value_ = remote_fingerprint_value.Pass();
   remote_fingerprint_algorithm_ = digest_alg;
 
-  bool reconnect = dtls_;
-
   if (!SetupDtls()) {
     set_dtls_state(DTLS_TRANSPORT_FAILED);
     return false;
   }
 
-  if (reconnect) {
-    Reconnect();
-  }
-
   return true;
 }
 
@@ -540,13 +530,8 @@ void DtlsTransportChannelWrapper::OnDtlsEvent(rtc::StreamInterface* dtls,
   if (sig & rtc::SE_READ) {
     char buf[kMaxDtlsPacketLen];
     size_t read;
-    rtc::StreamResult result = dtls_->Read(buf, sizeof(buf), &read, NULL);
-    if (result == rtc::SR_SUCCESS) {
+    if (dtls_->Read(buf, sizeof(buf), &read, NULL) == rtc::SR_SUCCESS) {
       SignalReadPacket(this, buf, read, rtc::CreatePacketTime(0), 0);
-    } else if (result == rtc::SR_EOS) {
-      // If the SSL stream has closed remotely, reset the |sig| to be SE_CLOSE
-      // so it could be handled below.
-      sig = rtc::SE_CLOSE;
     }
   }
   if (sig & rtc::SE_CLOSE) {
@@ -631,12 +616,4 @@ void DtlsTransportChannelWrapper::OnConnectionRemoved(
   SignalConnectionRemoved(this);
 }
 
-void DtlsTransportChannelWrapper::Reconnect() {
-  set_dtls_state(DTLS_TRANSPORT_NEW);
-  set_writable(false);
-  if (channel_->writable()) {
-    OnWritableState(channel_);
-  }
-}
-
 }  // namespace cricket