Add support for cellular geolocation

chromeos/geolocation/simple_geolocation_provider.cc

Index: chromeos/geolocation/simple_geolocation_provider.cc
diff --git a/chromeos/geolocation/simple_geolocation_provider.cc b/chromeos/geolocation/simple_geolocation_provider.cc
index 45d6981dcb8b08bdf1d25cbf8ec6dc848915c429..a030ecf62b7f15bd233d0bc06333bad68c22c1e0 100644
--- a/chromeos/geolocation/simple_geolocation_provider.cc
+++ b/chromeos/geolocation/simple_geolocation_provider.cc
@@ -34,6 +34,22 @@ std::unique_ptr<WifiAccessPointVector> GetAccessPointData() {
   return result;
 }
 
+std::unique_ptr<CellTowerVector> GetCellTowerData() {
+  if (!chromeos::NetworkHandler::Get()
+           ->geolocation_handler()
+           ->cellular_enabled()) {
+    return nullptr;
+  }
+
+  auto result = base::MakeUnique<chromeos::CellTowerVector>();
+  int64_t age_ms = 0;
+  if (!NetworkHandler::Get()->geolocation_handler()->GetCellTowers(result.get(),
+                                                                   &age_ms)) {
+    return nullptr;
+  }
+  return result;
+}
+
 }  // namespace
 
 SimpleGeolocationProvider::SimpleGeolocationProvider(
@@ -49,12 +65,14 @@ SimpleGeolocationProvider::~SimpleGeolocationProvider() {
 void SimpleGeolocationProvider::RequestGeolocation(
     base::TimeDelta timeout,
     bool send_wifi_access_points,
+    bool send_cell_towers,
     SimpleGeolocationRequest::ResponseCallback callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   SimpleGeolocationRequest* request(new SimpleGeolocationRequest(
       url_context_getter_.get(), url_, timeout,
-      send_wifi_access_points ? GetAccessPointData() : nullptr));
+      send_wifi_access_points ? GetAccessPointData() : nullptr,
+      send_cell_towers ? GetCellTowerData() : nullptr));

[Alexander Alekseev, 2017/02/06 23:24:53]

This is not optimal, as both GetAccessPointData() / GetCellTowerData() initiate
DBUS requests. Could you change API so that only one DBUS request is initiated
here? May be we should initiate request by a separate call to geolocation
handler, WDYT?

[can Skylar cook, 2017/02/07 21:32:39]

Good catch, agreed! I think it's useful to expose both methods in this class,
but will streamline the usage here.

[stevenjb, 2017/02/07 21:37:53]

That is a good point, each of these does send an identical request for
geolocation data. It would be better to replace
GeolocationHandler::GetWifiAccessPoints with a single method like
GeolocationHandler::GetGeolocationData(wifi_access_points.get(),
cell_tower_data.get(), &age_ms). The test for wifi/cellular_enabled can then be
moved to GeolocationHander (and may be able to be removed from the public API).

   requests_.push_back(base::WrapUnique(request));
 
   // SimpleGeolocationProvider owns all requests. It is safe to pass unretained