f01af7551b
In particular, if a new window was created out from under the drag, the drag-move event dispatch logic would wind up blithly assuming that it would find a valid touch-dispatchable window under the finger. When this was untrue, it would NPE, but the NPE was caught and discarded safely by higher-level guard code. With this change, we now avoid the NPE entirely and report the spurious condition as part of the debugging log stream. (Also add the local-state object to DragEvent.toString()'s output.) Change-Id: Idfa5f45d049e48415ee59c8b0ffb5b0ed4098ce3