| APZTestData.h | This structure is used to store information logged by various gecko
 components for later examination by test code.
 It contains a bucket for every paint (initiated on the client side),
 and every repaint request (initiated on the compositor side by
 AsyncPanZoomController::RequestContentRepait), which are identified by
 sequence numbers, and within that, a set of arbitrary string key/value
 pairs for every scrollable frame, identified by a scroll id.
 There are two instances of this data structure for every content thread:
 one on the client side and one of the compositor side.
 It also contains a list of hit-test results for MozMouseHittest events
 dispatched during testing. This list is only populated on the compositor
 instance of this class. | 9852 |