commit 960e27eea0a509153ee247d7edda7d1c4d49eb53
author tkent <tkent@chromium.org> Thu Jan 14 06:48:01 2016
committer Commit bot <commit-bot@chromium.org> Thu Jan 14 06:49:08 2016
tree efec1420d78af9267e8bd6d3c33d9da401a73dae
parent 3c5fdeeaf0e31f0982e1f457b54067b8dc2348fa

Add counters for <menuitem>.

- UseCounter::MenuItemElement
  Counts menuitem element usage.
  if chrome://flags/#enable-experimental-web-platform-features is enabled,
  HTMLMenuItemElement is used.  Otherwise, HTMLUnknownElement is used.

- UseCounter::MenuItemCloseTag
  Counts </menuitem>.  <menuitem> is a void element according to the current
  specification.  This counts wrong usages like crbug.com/412945.

BUG=412945

Review URL: https://codereview.chromium.org/1587673005

Cr-Commit-Position: refs/heads/master@{#369354}