Remove outdated devices from Android device chooser

device/bluetooth/bluetooth_device.h

Index: device/bluetooth/bluetooth_device.h
diff --git a/device/bluetooth/bluetooth_device.h b/device/bluetooth/bluetooth_device.h
index d851973f209d9f8a5febc4742a468555592cadf7..642f3318b71c8920e028ae811efd964be2ceeff4 100644
--- a/device/bluetooth/bluetooth_device.h
+++ b/device/bluetooth/bluetooth_device.h
@@ -18,6 +18,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
+#include "base/time/time.h"
 #include "device/bluetooth/bluetooth_export.h"
 #include "device/bluetooth/bluetooth_uuid.h"
 #include "net/log/net_log.h"
@@ -468,6 +469,12 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
   // empty string.
   static std::string CanonicalizeAddress(const std::string& address);
 
+  // Return the timestamp for when this device was last seen.
+  base::Time GetLastUpdateTime() const { return last_update_time_; }
+
+  // Update the last time this device was seen.
+  void UpdateTimestamp();
+
   // Return associated BluetoothAdapter.
   BluetoothAdapter* GetAdapter() { return adapter_; }
 
@@ -485,6 +492,7 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
   FRIEND_TEST_ALL_PREFIXES(BluetoothTest,
                            BluetoothGattConnection_DisconnectGatt_Cleanup);
   FRIEND_TEST_ALL_PREFIXES(BluetoothTest, GetDeviceName_NullName);
+  FRIEND_TEST_ALL_PREFIXES(BluetoothTest, RemoveOutdatedDevices);
 
   BluetoothDevice(BluetoothAdapter* adapter);
 
@@ -551,6 +559,9 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
   // the specific data. The data is stored as BinaryValue.
   std::unique_ptr<base::DictionaryValue> services_data_;
 
+  // Timestamp for when an advertisement was last seen.
+  base::Time last_update_time_;
+
  private:
   // Returns a localized string containing the device's bluetooth address and
   // a device type for display when |name_| is empty.