[Cast Channel] Add support for nonce challenge to Cast channel authentication.

extensions/browser/api/cast_channel/cast_socket.h

 // Copyright 2014 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.
 
 #ifndef EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_SOCKET_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_SOCKET_H_
 
 #include <stdint.h>
 
 #include <queue>
@@ skipping 127 matching lines @@
   // |channel_auth|. |owner_extension_id| is the id of the extension that opened
   // the socket.  |channel_auth| must not be CHANNEL_AUTH_NONE.
   // Parameters:
   // |owner_extension_id|: ID of the extension calling the API.
   // |ip_endpoint|: IP address of the remote host.
   // |channel_auth|: Authentication method used for connecting to a Cast
   //                 receiver.
   // |net_log|: Log of socket events.
   // |connect_timeout|: Connection timeout interval.
   // |logger|: Log of cast channel events.
+  // |nonce|: The nonce challenge.
   CastSocketImpl(const std::string& owner_extension_id,
                  const net::IPEndPoint& ip_endpoint,
                  ChannelAuthType channel_auth,
                  net::NetLog* net_log,
                  const base::TimeDelta& connect_timeout,
                  bool keep_alive,
                  const scoped_refptr<Logger>& logger,
-                 uint64_t device_capabilities);
+                 uint64_t device_capabilities,
+                 const std::string& nonce);
 
   // Ensures that the socket is closed.
   ~CastSocketImpl() override;
 
   // CastSocket interface.
   void Connect(std::unique_ptr<CastTransport::Delegate> delegate,
                base::Callback<void(ChannelError)> callback) override;
   CastTransport* transport() const override;
   void Close(const net::CompletionCallback& callback) override;
   const net::IPEndPoint& ip_endpoint() const override;
@@ skipping 206 matching lines @@
   // Cast message formatting and parsing layer.
   std::unique_ptr<CastTransport> transport_;
 
   // Caller's message read and error handling delegate.
   std::unique_ptr<CastTransport::Delegate> delegate_;
 
   // Raw pointer to the auth handshake delegate. Used to get detailed error
   // information.
   AuthTransportDelegate* auth_delegate_;
 
+  // The nonce challenge to send to the Cast receiver.
+  std::string nonce_;
+
   DISALLOW_COPY_AND_ASSIGN(CastSocketImpl);
 };
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_SOCKET_H_