Remove MicroData implementation

Per the discussion on blink-dev we should remove the MicroData implementation.
There's questions of quality, a maintainer, and that no port of WebKit ever
turned it on.

See: https://groups.google.com/a/chromium.org/forum/?fromgroups=#!topic/blink-dev/b54nW_mGSVU

R=ojan@chromium.org,abarth@chromium.org

Review URL: https://codereview.chromium.org/14028014

git-svn-id: svn://svn.chromium.org/blink/trunk@148315 bbb929c8-8fbe-4397-9dbb-9b2b20218538
200 files changed