Move the concept of multiple route into Network

webrtc/base/network.h

Index: webrtc/base/network.h
diff --git a/webrtc/base/network.h b/webrtc/base/network.h
index 8e5c8f0fb70e196acb1bab84321f1aa63812bf96..ef2c78f6733493e9500f618f2a72ca3ce4b466dd 100644
--- a/webrtc/base/network.h
+++ b/webrtc/base/network.h
@@ -56,6 +56,15 @@ class NetworkManager {
  public:
   typedef std::vector<Network*> NetworkList;
 
+  // This enum indicates the state of GetNetworks.
+  enum NetworkPermissionState {
+    STATE_UNKNOWN,  // SignalNetworksChanged is not fired yet.
+    STATE_ALLOWED,  // Adapter enumeration is allowed. Getting 0 network from
+                    // GetNetworks means that there is no network available.
+    STATE_BLOCKED   // Adapter enumeration is disabled. GetAnyAddressNetworks()
+                    // should be used instead.
+  };
+
   NetworkManager();
   virtual ~NetworkManager();
 
@@ -73,12 +82,15 @@ class NetworkManager {
   virtual void StopUpdating() = 0;
 
   // Returns the current list of networks available on this machine.
-  // UpdateNetworks() must be called before this method is called.
+  // StartUpdating() must be called before this method is called.
   // It makes sure that repeated calls return the same object for a
   // given network, so that quality is tracked appropriately. Does not
   // include ignored networks.
   virtual void GetNetworks(NetworkList* networks) const = 0;
 
+  // return the current permission state of GetNetworks()
+  virtual NetworkPermissionState network_permission_state() const = 0;
+
   // "AnyAddressNetwork" is a network which only contains single "any address"
   // IP address.  (i.e. INADDR_ANY for IPv4 or in6addr_any for IPv6). This is
   // useful as binding to such interfaces allow default routing behavior like
@@ -113,6 +125,10 @@ class NetworkManagerBase : public NetworkManager {
   void set_max_ipv6_networks(int networks) { max_ipv6_networks_ = networks; }
   int max_ipv6_networks() { return max_ipv6_networks_; }
 
+  NetworkPermissionState network_permission_state() const override {
+    return network_permission_state_;
+  }
+
  protected:
   typedef std::map<std::string, Network*> NetworkMap;
   // Updates |networks_| with the networks listed in |list|. If
@@ -127,10 +143,16 @@ class NetworkManagerBase : public NetworkManager {
                         bool* changed,
                         NetworkManager::Stats* stats);
 
+  void set_network_permission_state(NetworkPermissionState state) {
+    network_permission_state_ = state;
+  }
+
  private:
   friend class NetworkTest;
   void DoUpdateNetworks();
 
+  NetworkPermissionState network_permission_state_;
+
   NetworkList networks_;
   int max_ipv6_networks_;