Remove support for Document.createEvent() without argument

Remove support for Document.createEvent() without argument. This only worked
for SVG documents and for historical reasons. The UseCounter shows that
the feature is used by less than 0.0001% of pages.

The new behavior matches the specification:
http://dom.spec.whatwg.org/#dom-document-createevent

It also matches the behavior of Firefox 28 and IE11.

Intent to remove thread on blink-dev:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/INrADzxchrg

R=arv@chromium.org, eseidel@chromium.org
BUG=238366

Review URL: https://codereview.chromium.org/254133002

git-svn-id: svn://svn.chromium.org/blink/trunk@173314 bbb929c8-8fbe-4397-9dbb-9b2b20218538