Add database model worker to worker registry and remove deprecated thread check.
Add database model worker to worker registry and remove deprecated thread
check.

BUG=29926
TEST=Attempt to sync Autofill with a dev server.

Review URL: http://codereview.chromium.org/660343

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@40341 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser