
Small changes to the the event that is dispatched when the page is scrolled
while the user does a drag & drop action.

Every time the mouse changes position, a goog.fx.DragEvent is dispatched that
contains the client coordinates (relative
to the viewport) of the mouse. There are two cases where the mouse can change
position, the obvious one when it is moving, and the one where the page is
scrolling without any mouse movement, either because it is triggered by script
or if the user is moving the mouse wheel or using a gesture on a trackpad.

For the second case the mouse coordinates were so far updated based on the current scroll position, which is not necessary as their position relative to the viewport does not change.

This bug often produced negative coordinates in drag events which should now be correct.

R=pupius
DELTA=2  (0 added, 0 deleted, 2 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=2865


yamadatomonori/closure-library,yamadatomonori/closure-library,yamadatomonori/closure-library