<label> element should send key and focus events if it has contenteditable attribute.

HTMLLabelElement should be focusable if it passes the test isContentEditable(). As a result, the proper events would be sent.
Both Opera and Firefox support this behavior.

BUG=209871
TEST=fast/forms/label/labels-contenteditable.html

Review URL: https://chromiumcodereview.appspot.com/14985009

git-svn-id: svn://svn.chromium.org/blink/trunk@149973 bbb929c8-8fbe-4397-9dbb-9b2b20218538
4 files changed