Move LanguageState to the translate component

This CL introduces the TranslateDriver and a content implementation of it
(ContentTranslateDriver), and moves LanguageState to the translate component.
LanguageState gets information from the content driver through the
TranslateDriver API.

BUG=335092

Review URL: https://codereview.chromium.org/133273029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246023 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246023