Fixed crash when exiting page using GVR controller w/ the gamepad API

device/vr/android/gvr/gvr_gamepad_data_fetcher.h

Index: device/vr/android/gvr/gvr_gamepad_data_fetcher.h
diff --git a/device/vr/android/gvr/gvr_gamepad_data_fetcher.h b/device/vr/android/gvr/gvr_gamepad_data_fetcher.h
index 2e16c0b5d76ff8cbc2f40c22890bb3d05c99172d..d6eca677cc1cc5e299973db94a1e16e4804fa930 100644
--- a/device/vr/android/gvr/gvr_gamepad_data_fetcher.h
+++ b/device/vr/android/gvr/gvr_gamepad_data_fetcher.h
@@ -42,8 +42,8 @@ class GvrGamepadDataFetcher : public GamepadDataFetcher {
 
  private:
   std::unique_ptr<gvr::ControllerApi> controller_api_;
-  std::unique_ptr<gvr::UserPrefs> user_prefs_;
   gvr::ControllerState controller_state_;
+  gvr::ControllerHandedness handedness_;
   unsigned int display_id_;
 
   DISALLOW_COPY_AND_ASSIGN(GvrGamepadDataFetcher);