[CrOS Tether] Sort Tether network lists.

chromeos/network/network_state_handler.h

Index: chromeos/network/network_state_handler.h
diff --git a/chromeos/network/network_state_handler.h b/chromeos/network/network_state_handler.h
index d695b40186a6ce12f9f59ee5e9654933304b9435..5cfc503ce03f98a946799279872ba5c0ada8b8ec 100644
--- a/chromeos/network/network_state_handler.h
+++ b/chromeos/network/network_state_handler.h
@@ -69,6 +69,16 @@ class CHROMEOS_EXPORT NetworkStateHandler
   typedef std::vector<const NetworkState*> NetworkStateList;
   typedef std::vector<const DeviceState*> DeviceStateList;
 
+  // Sorts Tether networks. Because sorting rules are determined by the Tether
+  // component, a delegate is required to sort the list.
+  class TetherNetworkListSorter {

[stevenjb, 2017/06/21 20:59:04]

This should probably have Delegate in the name, maybe just TetherSortDelegate?

[Kyle Horimoto, 2017/06/21 22:17:07]

Done.

+   public:
+    // Sorts the list so that the highest-priority networks are in the front of
+    // the list.
+    virtual void SortTetherNetworkList(
+        ManagedStateList* tether_networks) const = 0;
+  };
+
   enum TechnologyState {
     TECHNOLOGY_UNAVAILABLE,
     TECHNOLOGY_AVAILABLE,
@@ -267,6 +277,10 @@ class CHROMEOS_EXPORT NetworkStateHandler
   // provided |guid| to "Connected". This will be reflected in the UI.
   void SetTetherNetworkStateConnected(const std::string& guid);
 
+  // Sets the sorting delegate for Tether networks.
+  void SetTetherNetworkListSorter(
+      const TetherNetworkListSorter* tether_network_list_sorter);

[stevenjb, 2017/06/21 20:59:04]

I wouldn't bother to check the tether technology state here, that really just
potentially creates initialization order issues which shouldn't matter (e.g. if
we set this delegate before initializing the technology; we should handle that
in the Sorter implementation instead, if at all).

Then we can just make this an in line set_tether_... method.

[Kyle Horimoto, 2017/06/21 22:17:07]

Done.

+
   // Sets |list| to contain the list of devices.  The returned list contains
   // a copy of DeviceState pointers which should not be stored or used beyond
   // the scope of the calling function (i.e. they may later become invalid, but
@@ -523,6 +537,9 @@ class CHROMEOS_EXPORT NetworkStateHandler
   TechnologyState tether_technology_state_ =
       TechnologyState::TECHNOLOGY_UNAVAILABLE;
 
+  // Not owned by this instance.
+  const TetherNetworkListSorter* tether_network_list_sorter_ = nullptr;
+
   // Ensure that Shutdown() gets called exactly once.
   bool did_shutdown_ = false;