Do not pass URLs in onUpdated events to extensions unless they have the
"tabs" permission.

BUG=168442


Review URL: https://chromiumcodereview.appspot.com/11824004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@176406 0039d316-1c4b-4281-b951-d872f2087c98
MessageService::~MessageService() {
  STLDeleteContainerPairSecondPointers(channels_.begin(), channels_.end());
  channels_.clear();
}

MessageService::~MessageService() {
  STLDeleteContainerPairSecondPointers(channels_.begin(), channels_.end());
  channels_.clear();
}
