Oilpan: disconnected scrollbars must be externally observable as such.
Followup the Scrollbar and ScrollableArea Oilpan changes in r198064, and
have explicit disconnects of Scrollbars from their ScrollableAreas be
observable via the Scrollbar afterwards.
The assumption made in r198064 that no one wanted to observe Scrollbars
in that detached/disconnected state, doesn't hold. SelectorChecker and
AXScrollbar are two examples.
R=haraken
BUG=504655
Review URL: https://codereview.chromium.org/1215063006
git-svn-id: svn://svn.chromium.org/blink/trunk@198144 bbb929c8-8fbe-4397-9dbb-9b2b20218538
1 file changed
