Oilpan: Move DeviceSingleWindowEventController to oilpan's heap

Currently DeviceLightController, DeviceMotionController
and DeviceOrientationController are on the heap,
but DeviceSingleWindowEventController (which is a
parent class of the three classes) is not on the heap.
We should move DeviceSingleWindowEventController to
the heap and trace DeviceSingleWindowEventController::m_document.

BUG=340522

Review URL: https://codereview.chromium.org/435743003

git-svn-id: svn://svn.chromium.org/blink/trunk@179408 bbb929c8-8fbe-4397-9dbb-9b2b20218538