Layout as necessary on positioned movement with opacity or filter changes

r163926[1] caused RenderStyle::diff to set context specific properties
even when the result required a layout. This caused certain changes such
as an opacity change together with a positioned movment to be treated as
only a repaint after the logic in RenderObject::adjustStyleDifference
was applied. This patch makes adjustStyleDifference consider such cases.

[1] https://src.chromium.org/viewvc/blink?view=rev&revision=163926

BUG=335780

Review URL: https://codereview.chromium.org/145003008

git-svn-id: svn://svn.chromium.org/blink/trunk@165702 bbb929c8-8fbe-4397-9dbb-9b2b20218538