Remove ContainerNode overload for ElementTraversal::previous()

Remove ContainerNode overload for NodeTraversal::previous() as it adds no
benefit compared to the one taking a Node in argument.

The ElementTraversal::previous() implementation calls NodeTraversal::previous()
which does not have a ContainerNode overload. The NodeTraversal::previous()
implementation calls previousSibling() and parentNode() on the argument so
having a ContainerNode overload for it wouldn't help as those operations are
fast on pure Nodes.

R=esprehn@chromium.org, adamk@chromium.org

Review URL: https://codereview.chromium.org/425033002

git-svn-id: svn://svn.chromium.org/blink/trunk@179163 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Styling for blackbox regex UI dialog.

Make disabled regex text lines line-through styled.

BUG=267592
R=vsevik

Review URL: https://codereview.chromium.org/423153002

git-svn-id: svn://svn.chromium.org/blink/trunk@179164 bbb929c8-8fbe-4397-9dbb-9b2b20218538