Land Recent QUIC changes.

net/tools/quic/quic_dispatcher.cc

Index: net/tools/quic/quic_dispatcher.cc
diff --git a/net/tools/quic/quic_dispatcher.cc b/net/tools/quic/quic_dispatcher.cc
index 14de2b0b40ed7cf8aa562481cd44e02109e360a9..c84b4e8cbef9013932db0d99cc41be94e0cc62e8 100644
--- a/net/tools/quic/quic_dispatcher.cc
+++ b/net/tools/quic/quic_dispatcher.cc
@@ -58,6 +58,12 @@ int QuicDispatcher::WritePacket(const char* buffer, size_t buf_len,
                                 const IPEndPoint& peer_address,
                                 QuicBlockedWriterInterface* writer,
                                 int* error) {
+  if (write_blocked_) {
+    write_blocked_list_.AddBlockedObject(writer);
+    *error = EAGAIN;
+    return -1;
+  }
+
   int rc = QuicSocketUtils::WritePacket(fd_, buffer, buf_len,
                                         self_address, peer_address,
                                         error);