[CrOS Tether] Create HostScanCache, which caches scan results and inserts them into the network sta…

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 b35887bd5aa6f0629d9fa06fe540d20476548414..9e9e4a7d84006fabd7ce1b46bf65b00404656035 100644
--- a/chromeos/network/network_state_handler.h
+++ b/chromeos/network/network_state_handler.h
@@ -209,13 +209,12 @@ class CHROMEOS_EXPORT NetworkStateHandler
   // network. The |guid| provided must be non-empty. If a network with |guid|
   // already exists, this method will do nothing. Use the provided |guid| to
   // refer to and fetch this NetworkState in the future.
-  // NOTE: only GetNetworkStateFromGuid is supported to fetch "tether"
-  // NetworkStates.
   void AddTetherNetworkState(const std::string& guid,
                              const std::string& name,
                              const std::string& carrier,
                              int battery_percentage,
-                             int signal_strength);
+                             int signal_strength,
+                             bool has_connected_to_host);

[Ryan Hansberry, 2017/04/28 22:31:04]

Please explain this argument in the documentation, and please consider a more
clear name -- right now it sounds like a description of the network itself
instead of our relationship to it, i.e. "this tether network has connected to a
host before" as opposed to "we have connected to this tether network before".
Perhaps 'has_been_connected_to_before', etc.

Unfortunately it seems this name is already established in the codebase so I do
not feel strongly about this.

[Kyle Horimoto, 2017/04/28 22:45:04]

Changed the description.

We talked about this naming scheme last week and decided on it together :P. To
jog your memory, we decided that "has_been_connected_to_before" doesn't make
sense because it describes whether this individual network has been connected
to. What we want to know is whether we've connected to the tether host which is
providing this network before.

 
   // Updates the tether properties (carrier, battery percentage, and signal
   // strength) for a network which has already been added via
@@ -225,9 +224,16 @@ class CHROMEOS_EXPORT NetworkStateHandler
                                      int battery_percentage,
                                      int signal_strength);
 
+  // Updates the HasConnectedToHost property of the Tether network with GUID
+  // |guid| to true. If no network with GUID |guid| is registered or if the
+  // network is registered and its HasConnectedToHost value was already true,

[Ryan Hansberry, 2017/04/28 22:31:04]

I assume this shouldn't be camel-case and should be like
|has_connected_to_host_|? Might be wrong though.

[Kyle Horimoto, 2017/04/28 22:45:04]

I named it that way because this is the name of the ONC property, but I realize
that isn't exactly clear since this file doesn't deal with ONC properties. I
reworded it.

+  // this function does nothing. Returns whether the value was actually changed.
+  bool SetTetherNetworkHasConnectedToHost(const std::string& guid);
+
   // Remove a Tether NetworkState, using the same |guid| passed to
-  // AddTetherNetworkState.
-  void RemoveTetherNetworkState(const std::string& guid);
+  // AddTetherNetworkState(). If no network with GUI |guid| is registered, this
+  // function does nothing. Returns whether the network was actually removed.
+  bool RemoveTetherNetworkState(const std::string& guid);
 
   // Inform NetworkStateHandler that the provided Tether network with the
   // provided guid |tether_network_guid| is associated with the Wi-Fi network