Add encoding info for those WebUI pages that were missing it.
Prevents encoding detection issues on those pages.

BUG=329890

Review URL: https://codereview.chromium.org/117713003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241926 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241926