Add use-counters for some HTML elements.

- <details>
- <dialog>
- <map>
- <meter>
- <progress>

BUG=

Review URL: https://codereview.chromium.org/392833003

git-svn-id: svn://svn.chromium.org/blink/trunk@178294 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Clean up some CSS nits in sheriff-o-matic

I've removed the horizontal line, which was just visual noise. I also moved the
margin and padding for the failure cards to their embedder, which is a better
practice.

NOTRY=true

Review URL: https://codereview.chromium.org/394323003

git-svn-id: svn://svn.chromium.org/blink/trunk@178295 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Oilpan: remove now-unused WebNode(Member<T>) constructor.

The (implicit) construction of a WebNode from a Member<T> (where T is
convertible to a Node) was introduced to allow for assignment of a
Member<Element> to a WebNode (as needed by http://crrev.com/280123002/)

With http://crrev.com/313813002 (r175522), an operator conversion from
Member<T> to RawPtr<T> was introduced, which makes the reason for having
the above WebNode() constructor fall away. Remove it here.

R=abarth@chromium.org
BUG=357163
NOTRY=true

Review URL: https://codereview.chromium.org/400473002

git-svn-id: svn://svn.chromium.org/blink/trunk@178296 bbb929c8-8fbe-4397-9dbb-9b2b20218538