Generate thread-safe EventTargetNames

This CL prepares us to replace thread-local EventTargetNames with thread-safe
EventTargetNames. I've also taken this opportunity to clean up some of the
other in-file machinery.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/26651004

git-svn-id: svn://svn.chromium.org/blink/trunk@159292 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Dispatch [DOM]FocusIn/Out events when the page changes focus.

When the page loses focus dispatch focusout and DOMFocusOut events in addition to the blur event. When the page regains focus, dispatch focusin and DOMFocusIn events in addition to the focus event.

R=tkent@chromium.org
BUG=

Review URL: https://codereview.chromium.org/26761003

git-svn-id: svn://svn.chromium.org/blink/trunk@159293 bbb929c8-8fbe-4397-9dbb-9b2b20218538