Remove outdated devices from Android device chooser

device/bluetooth/bluetooth_adapter.cc

Index: device/bluetooth/bluetooth_adapter.cc
diff --git a/device/bluetooth/bluetooth_adapter.cc b/device/bluetooth/bluetooth_adapter.cc
index 09127f981cb48ec266570c74a803285da6f33141..d10faea101ab31ce7383bd18f1d58289f5c27b0f 100644
--- a/device/bluetooth/bluetooth_adapter.cc
+++ b/device/bluetooth/bluetooth_adapter.cc
@@ -365,6 +365,38 @@ BluetoothAdapter::GetMergedDiscoveryFilterHelper(
   return result;
 }
 
+void BluetoothAdapter::RemoveTimedOutDevices() {
+  for (DevicesMap::iterator it = devices_.begin(); it != devices_.end();) {
+    BluetoothDevice* device = it->second;
+    if (device->IsPaired() || device->IsConnected() ||
+        device->IsGattConnected()) {
+      ++it;
+      continue;
+    }
+
+    base::Time last_update_time = device->GetLastUpdateTime();
+
+    bool device_expired =
+        (base::Time::NowFromSystemTime() - last_update_time) > timeoutSec;
+    VLOG(1) << "device: " << device->GetAddress()
+            << ", last_update: " << last_update_time
+            << ", exp: " << device_expired;
+
+    if (!device_expired) {
+      ++it;
+      continue;
+    }
+    DevicesMap::iterator next = it;
+    next++;
+    std::unique_ptr<BluetoothDevice> removed_device =
+        devices_.take_and_erase(it);
+    it = next;

[ortuno, 2016/06/23 15:42:59]

Any special reason why you manually copy and increase the iterator? We just put
the ++it in the for loop in a couple of places[1][2][3] and I would like to know
if this is a pattern we should follow there as well. If not then I would prefer
the existing pattern already to be consistent throughout the code base.

[1]
https://cs.chromium.org/chromium/src/device/bluetooth/bluetooth_adapter_win.c...
[2]
https://cs.chromium.org/chromium/src/device/bluetooth/bluez/bluetooth_adapter...
[3]
https://cs.chromium.org/chromium/src/device/bluetooth/bluez/bluetooth_adapter...

[ortuno, 2016/06/23 17:57:33]

Discussed this with scheib. I see why this is the correct approach and we should
fix other instances of the broken pattern. No need for you to do anything.

+
+    FOR_EACH_OBSERVER(BluetoothAdapter::Observer, observers_,
+                      DeviceRemoved(this, removed_device.get()));
+  }
+}
+
 // static
 void BluetoothAdapter::RecordBluetoothDiscoverySessionStartOutcome(
     UMABluetoothDiscoverySessionOutcome outcome) {
@@ -381,4 +413,8 @@ void BluetoothAdapter::RecordBluetoothDiscoverySessionStopOutcome(
       static_cast<int>(UMABluetoothDiscoverySessionOutcome::COUNT));
 }
 
+// static
+const base::TimeDelta BluetoothAdapter::timeoutSec =
+    base::TimeDelta::FromSeconds(180);
+
 }  // namespace device