Add 16-bit network id to the candidate signaling.

webrtc/p2p/base/candidate.h

Index: webrtc/p2p/base/candidate.h
diff --git a/webrtc/p2p/base/candidate.h b/webrtc/p2p/base/candidate.h
index 11481cdb05a972db4237d3ef961cea6b0bc7e066..4ab1b6f2356daecbc900deedff8c5e72644f392f 100644
--- a/webrtc/p2p/base/candidate.h
+++ b/webrtc/p2p/base/candidate.h
@@ -27,7 +27,7 @@
 
 namespace cricket {
 
-const uint32_t kMaxNetworkCost = 999;
+const uint16_t kMaxNetworkCost = 999;
 
 // Candidate for ICE based connection discovery.
 
@@ -40,7 +40,9 @@ class Candidate {
         component_(0),
         priority_(0),
         network_type_(rtc::ADAPTER_TYPE_UNKNOWN),
-        generation_(0) {}
+        generation_(0),
+        network_id_(0),
+        network_cost_(0) {}
 
   Candidate(int component,
             const std::string& protocol,
@@ -50,7 +52,9 @@ class Candidate {
             const std::string& password,
             const std::string& type,
             uint32_t generation,
-            const std::string& foundation)
+            const std::string& foundation,
+            uint16_t network_id = 0,
+            uint16_t network_cost = 0)
       : id_(rtc::CreateRandomString(8)),
         component_(component),
         protocol_(protocol),
@@ -61,7 +65,9 @@ class Candidate {
         type_(type),
         network_type_(rtc::ADAPTER_TYPE_UNKNOWN),
         generation_(generation),
-        foundation_(foundation) {}
+        foundation_(foundation),
+        network_id_(network_id),
+        network_cost_(network_cost) {}
 
   const std::string & id() const { return id_; }
   void set_id(const std::string & id) { id_ = id; }
@@ -143,11 +149,15 @@ class Candidate {
   // |network_cost| measures the cost/penalty of using this candidate. A network
   // cost of 0 indicates this candidate can be used freely. A value of
   // |kMaxNetworkCost| indicates it should be used only as the last resort.
-  void set_network_cost(uint32_t network_cost) {
+  void set_network_cost(uint16_t network_cost) {
     ASSERT(network_cost <= kMaxNetworkCost);
     network_cost_ = network_cost;
   }
-  uint32_t network_cost() const { return network_cost_; }
+  uint16_t network_cost() const { return network_cost_; }
+
+  // An ID assigned to the network hosting the candidate.
+  uint16_t network_id() const { return network_id_; }
+  void set_network_id(uint16_t network_id) { network_id_ = network_id; }
 
   const std::string& foundation() const {
     return foundation_;
@@ -178,13 +188,14 @@ class Candidate {
   // Determines whether this candidate is equivalent to the given one.
   bool IsEquivalent(const Candidate& c) const {
     // We ignore the network name, since that is just debug information, and
-    // the priority, since that should be the same if the rest is (and it's
-    // a float so equality checking is always worrisome).
+    // the priority and the network cost, since they should be the same if the
+    // rest are.
     return (component_ == c.component_) && (protocol_ == c.protocol_) &&
            (address_ == c.address_) && (username_ == c.username_) &&
            (password_ == c.password_) && (type_ == c.type_) &&
            (generation_ == c.generation_) && (foundation_ == c.foundation_) &&
-           (related_address_ == c.related_address_);
+           (related_address_ == c.related_address_) &&
+           (network_id_ == c.network_id_);
   }
 
   // Determines whether this candidate can be considered equivalent to the
@@ -238,7 +249,7 @@ class Candidate {
     ost << "Cand[" << transport_name_ << ":" << foundation_ << ":" << component_
         << ":" << protocol_ << ":" << priority_ << ":" << address << ":"
         << type_ << ":" << related_address_ << ":" << username_ << ":"
-        << password_ << ":" << network_cost_ << "]";
+        << password_ << ":" << network_id_ << ":" << network_cost_ << "]";
     return ost.str();
   }
 
@@ -257,8 +268,9 @@ class Candidate {
   std::string foundation_;
   rtc::SocketAddress related_address_;
   std::string tcptype_;
-  uint32_t network_cost_ = 0;
   std::string transport_name_;
+  uint16_t network_id_;
+  uint16_t network_cost_;
 };
 
 // Used during parsing and writing to map component to channel name