Android WebView: initialize url_util safely.

In the case where we use CookieManager before initializing the rest of
Chromium, we need to have initialized url_util at some reliable point
because its lazy init is not threadsafe. Do this in the entry point so
it's guaranteed we've always called it before any Chromium code runs.

BUG=334490

Review URL: https://codereview.chromium.org/136723010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245084 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245084