Correct NSScreen comparison on PPAPI fullscreen switching

From OS X 10.10, NSApplicationDidChangeScreenParametersNotification
will be sent when window enters fullscreen, and [NSScreen screens]
will be updated with new NSScreen instances equal to the previous
ones but with different pointer values. As a result, using == to
compare pointers of desiredScreen and current menu bar/dock screen
will break as the containsObject: check in -update does isEqual:

This doesn't affect Chrome as Chrome is using EmbedsFullscreenWidget().

Review URL:

Cr-Commit-Position: refs/heads/master@{#298989}
1 file changed