Move UI code out of TranslateManager
The UI code is dependent on the embedder of Translate, and thus is moved
out of TranslateManager (which is intended to deal only with core logic).
The UI code is moved in TranslateTabHelper, which is the main embedder class for
Translate. The |use_infobar_| global state is moved to TranslateService which is
the singleton dealing with Translate global state.
The ShortcutConfig class (related to translate infobars) is removed as it was
not used.
BUG=336249
TBR=jochen
Review URL: https://codereview.chromium.org/
136643009
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250142 0039d316-1c4b-4281-b951-d872f2087c98