Enable TURN on the host when using WebRTC.

remoting/protocol/transport_context.h

 // Copyright 2015 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 REMOTING_PROTOCOL_TRANSPORT_CONTEXT_H_
 #define REMOTING_PROTOCOL_TRANSPORT_CONTEXT_H_
 
+#include <array>
 #include <list>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "remoting/protocol/ice_config.h"
 #include "remoting/protocol/network_settings.h"
 #include "remoting/protocol/transport.h"
 
 namespace remoting {
 
 class SignalStrategy;
 class UrlRequestFactory;
 
 namespace protocol {
 
 class PortAllocatorFactory;
 class IceConfigRequest;
 
 // TransportContext is responsible for storing all parameters required for
 // P2P transport initialization. It's also responsible for fetching STUN and
 // TURN configuration.
 class TransportContext : public base::RefCountedThreadSafe<TransportContext> {
  public:
+  enum RelayMode {
+    GTURN,
+    TURN
+  };
+  static const int kNumRelayModes = RelayMode::TURN + 1;

[garykac, 2016/03/15 20:38:59]

The enum should end with MAX_RELAYMODE (or something like that), and we should
use that value instead of TURN+1.

If someone adds a new RelayMode at the end of the enum, then this code will
break.

[Sergey Ulanov, 2016/03/15 21:54:53]

That would make the compiler complain that MAX_RELAYMODE is not handled in
switch statement in TransportContext::EnsureFreshIceConfig(). It's rather
obvious that this value need to be updated if a new mode needs to be added, but
it's also unlikely that we will ever need to add another value here. 

[garykac, 2016/03/16 00:58:21]

enum RelayMode {
  GTURN,
  TURN,
  LAST_RELAYMODE = TURN
};
static count int kNumRelayModes = RelayMode::LAST_RELAYMODE + 1;

[Sergey Ulanov, 2016/03/16 18:34:13]

Done.

+
   typedef base::Callback<void(const IceConfig& ice_config)>
       GetIceConfigCallback;
 
   static scoped_refptr<TransportContext> ForTests(TransportRole role);
 
   TransportContext(SignalStrategy* signal_strategy,
                    scoped_ptr<PortAllocatorFactory> port_allocator_factory,
                    scoped_ptr<UrlRequestFactory> url_request_factory,
                    const NetworkSettings& network_settings,
                    TransportRole role);
 
-  // Enables standard TURN servers.
-  void UseTurn(const std::string& ice_config_url) {
+  void set_ice_config_url(const std::string& ice_config_url) {
     ice_config_url_ = ice_config_url;
   }
 
+  // Sets relay mode for all future calls of GetIceConfig(). Doesn't affect
+  // previous GetIceConfig() requests.
+  void set_relay_mode(RelayMode relay_mode) { relay_mode_ = relay_mode; }
+
   // Prepares fresh JingleInfo. It may be called while connection is being
   // negotiated to minimize the chance that the following GetIceConfig() will
   // be blocking.
   void Prepare();
 
   // Requests fresh STUN and TURN information.
   void GetIceConfig(const GetIceConfigCallback& callback);
 
   PortAllocatorFactory* port_allocator_factory() {
     return port_allocator_factory_.get();
   }
   UrlRequestFactory* url_request_factory() {
     return url_request_factory_.get();
   }
   const NetworkSettings& network_settings() const { return network_settings_; }
   TransportRole role() const { return role_; }
 
  private:
   friend class base::RefCountedThreadSafe<TransportContext>;
 
   ~TransportContext();
 
-  void EnsureFreshJingleInfo();
-  void OnIceConfig(const IceConfig& ice_config);
+  void EnsureFreshIceConfig();
+  void OnIceConfig(RelayMode relay_mode, const IceConfig& ice_config);
 
   SignalStrategy* signal_strategy_;
   scoped_ptr<PortAllocatorFactory> port_allocator_factory_;
   scoped_ptr<UrlRequestFactory> url_request_factory_;
   NetworkSettings network_settings_;
   TransportRole role_;
 
   std::string ice_config_url_;
+  RelayMode relay_mode_ = RelayMode::GTURN;
 
-  scoped_ptr<IceConfigRequest> ice_config_request_;
+  std::array<scoped_ptr<IceConfigRequest>, kNumRelayModes> ice_config_request_;
+  std::array<IceConfig, kNumRelayModes> ice_config_;
 
-  IceConfig ice_config_;
-
-  // When there is an active |jingle_info_request_| stores list of callbacks to
+  // When there is an active |ice_config_request_| stores list of callbacks to
   // be called once the request is finished.
-  std::list<GetIceConfigCallback> pending_ice_config_callbacks_;
+  std::array<std::list<GetIceConfigCallback>, kNumRelayModes>
+      pending_ice_config_callbacks_;
 
   DISALLOW_COPY_AND_ASSIGN(TransportContext);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_TRANSPORT_CONTEXT_H_