Add SetProperty() in the PPB_Transport_Dev interface.

content/renderer/p2p/p2p_transport_impl.cc

Index: content/renderer/p2p/p2p_transport_impl.cc
diff --git a/content/renderer/p2p/p2p_transport_impl.cc b/content/renderer/p2p/p2p_transport_impl.cc
index 3f65b3e0259aa23a75f3addda6f2c618c9883e64..2458b8e0a81b505836135234ebd31d9b962cb029 100644
--- a/content/renderer/p2p/p2p_transport_impl.cc
+++ b/content/renderer/p2p/p2p_transport_impl.cc
@@ -40,7 +40,7 @@ P2PTransportImpl::~P2PTransportImpl() {
 
 bool P2PTransportImpl::Init(const std::string& name,
                             Protocol protocol,
-                            const std::string& config,
+                            const Config& config,
                             EventHandler* event_handler) {
   DCHECK(event_handler);
 
@@ -51,8 +51,7 @@ bool P2PTransportImpl::Init(const std::string& name,
   name_ = name;
   event_handler_ = event_handler;
 
-  // TODO(sergeyu): Implement PortAllocator that can parse |config|
-  // and use it here instead of BasicPortAllocator.
+  // TODO(sergeyu): Use STUN/Relay settings from |config|.
   allocator_.reset(new cricket::BasicPortAllocator(
       network_manager_.get(), socket_factory_.get()));