Tether: Persist if first-time setup is required to HostScanCache.

chromeos/components/tether/host_scan_cache.h

Index: chromeos/components/tether/host_scan_cache.h
diff --git a/chromeos/components/tether/host_scan_cache.h b/chromeos/components/tether/host_scan_cache.h
index 3d705e48887befdade932759600fb22c07be863b..762f3ef9715cfee5f1690c3e257572918f0670f7 100644
--- a/chromeos/components/tether/host_scan_cache.h
+++ b/chromeos/components/tether/host_scan_cache.h
@@ -58,11 +58,15 @@ class HostScanCache : public TetherHostResponseRecorder::Observer {
   // Note: |signal_strength| should be in the range [0, 100]. This is different
   // from the |connection_strength| field received in ConnectTetheringResponse
   // and KeepAliveTickleResponse messages (the range is [0, 4] in those cases).
+  // |battery_percentage| should also be in the range [0, 100].
+  // |setup_required| indicates that the host device requires first-time setup,
+  // i.e., user interaction to allow tethering.
   virtual void SetHostScanResult(const std::string& tether_network_guid,
                                  const std::string& device_name,
                                  const std::string& carrier,
                                  int battery_percentage,
-                                 int signal_strength);
+                                 int signal_strength,
+                                 bool setup_required);
 
   // Removes the scan result with GUID |tether_network_guid| from the cache. If
   // no cache result with that GUID was present in the cache, this function is
@@ -74,6 +78,10 @@ class HostScanCache : public TetherHostResponseRecorder::Observer {
   // connecting/connected to ensure the UI is up to date.
   virtual void ClearCacheExceptForActiveHost();
 
+  // Returns true if the host device requires first-time setup, i.e., user
+  // interaction to allow tethering.
+  virtual bool DoesHostRequireSetup(const std::string& tether_network_guid);
+
   // TetherHostResponseRecorder::Observer:
   void OnPreviouslyConnectedHostIdsChanged() override;
 
@@ -99,6 +107,7 @@ class HostScanCache : public TetherHostResponseRecorder::Observer {
   // host).
   std::unordered_map<std::string, std::unique_ptr<base::Timer>>
       tether_guid_to_timer_map_;
+  std::unordered_set<std::string> setup_required_tether_guids_;
   base::WeakPtrFactory<HostScanCache> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HostScanCache);