Move GetSiteForExtensionId() from ExtensionService to extension_util

BUG=351891
[email protected] (c/b/sync_file_system)
[email protected] (c/b/chromeos/file_manager)
(No functional difference for either TBR)

Review URL: https://codereview.chromium.org/198053005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257297 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed