Add 'explicit' to the PacketWriterFactoryAdapter constructor, as

net/tools/quic/quic_dispatcher.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A server side dispatcher which dispatches a given client's data to their
 // stream.
 
 #ifndef NET_TOOLS_QUIC_QUIC_DISPATCHER_H_
 #define NET_TOOLS_QUIC_QUIC_DISPATCHER_H_
 
@@ skipping 180 matching lines @@
  private:
   class QuicFramerVisitor;
   friend class net::tools::test::QuicDispatcherPeer;
 
   // An adapter that creates packet writers using the dispatcher's
   // PacketWriterFactory and shared writer. Essentially, it just curries the
   // writer argument away from QuicDispatcher::PacketWriterFactory.
   class PacketWriterFactoryAdapter :
     public QuicConnection::PacketWriterFactory {
    public:
-    PacketWriterFactoryAdapter(QuicDispatcher* dispatcher);
+    explicit PacketWriterFactoryAdapter(QuicDispatcher* dispatcher);
     ~PacketWriterFactoryAdapter() override;
 
     QuicPacketWriter* Create(QuicConnection* connection) const override;
 
    private:
     QuicDispatcher* dispatcher_;
   };
 
   // Called by |framer_visitor_| when the private header has been parsed
   // of a data packet that is destined for the time wait manager.
@@ skipping 51 matching lines @@
   QuicFramer framer_;
   scoped_ptr<QuicFramerVisitor> framer_visitor_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicDispatcher);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_DISPATCHER_H_