chromeos/dbus: Add fake D-Bus clients for GATT client-mode.

chromeos/dbus/fake_bluetooth_device_client.h

Index: chromeos/dbus/fake_bluetooth_device_client.h
diff --git a/chromeos/dbus/fake_bluetooth_device_client.h b/chromeos/dbus/fake_bluetooth_device_client.h
index c1699becec4a42cd95be1f6ac37773b2fe2429a3..827fdcb94cc3ec4b2aae46685c84edf161da6122 100644
--- a/chromeos/dbus/fake_bluetooth_device_client.h
+++ b/chromeos/dbus/fake_bluetooth_device_client.h
@@ -159,6 +159,11 @@ class CHROMEOS_EXPORT FakeBluetoothDeviceClient
   static const char kJustWorksAddress[];
   static const uint32 kJustWorksClass;
 
+  static const char kLowEnergyPath[];
+  static const char kLowEnergyName[];
+  static const char kLowEnergyAddress[];
+  static const uint32 kLowEnergyClass;
+
  private:
   // Property callback passed when we create Properties* structures.
   void OnPropertyChanged(const dbus::ObjectPath& object_path,
@@ -187,6 +192,10 @@ class CHROMEOS_EXPORT FakeBluetoothDeviceClient
       const dbus::ObjectPath& object_path,
       Properties* properties);
 
+  // Updates the RSSI property of fake device with object path |object_path|
+  // to |rssi|, if the fake device exists.
+  void UpdateDeviceRSSI(const dbus::ObjectPath& object_path, int16 rssi);
+
   void PinCodeCallback(
       const dbus::ObjectPath& object_path,
       const base::Closure& callback,