ui: Move webui/ directory into base/

BUG=299841
TEST=ui_unittests, no behavior changes.
[email protected]

Review URL: https://codereview.chromium.org/26171003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228582 0039d316-1c4b-4281-b951-d872f2087c98
64 files changed