Fix usage of XShapeGetRectangles() in ui::WindowContainsPoint()
According to the GTK source:
"XShapeGetRectangles returns NULL in two situations:
* - the server doesn't support the SHAPE extension
* - the shape is empty"
The spec does not mention anything about returning NULL when the shape is empty. In practice, XShapeGetRectangles() returns NULL on Unity when a window is minimized.
This CL fixes ui::WindowContainsPoint() to take the empty case into account
BUG=None
TEST=None
Review URL: https://codereview.chromium.org/
244693004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265497 0039d316-1c4b-4281-b951-d872f2087c98