Crash test for 400997.
Scrollbars can be kept alive referenced from the EventHandler after they
have been detached from their ScrollableAreas (through
m_lastScrollbarUnderMouse and m_scrollbarHandlingScrollGesture).
EventHandler may call setHoveredPart and setPressedPart on custom scroll-
bars (LayoutScrollbar) on mouse moves after these bars have been detached
from their scrollable areas. Those methods recalculate style for custom
scrollbar pseudo elements. That caused a crash in SelectorChecker for
the :corner-present pseudo class because it used the scrollableArea()
from Scrollbar without null-checking it.
The null-check was added as a speculative fix in r191244. This CL adds a
test which causes that crasher.
R=keishi@chromium.org,tkent@chromium.org
BUG=400997
Review URL: https://codereview.chromium.org/978753002
git-svn-id: svn://svn.chromium.org/blink/trunk@191278 bbb929c8-8fbe-4397-9dbb-9b2b20218538
2 files changed
