Fix crasher with autofill infobar.
The "save credit card" information was deleted by the AutofillManager when the form is submitted but was still pointed to by the TabContents, causing a crasher when navigating.

BUG=50428
TEST=See steps in 56238.

Review URL: http://codereview.chromium.org/3466006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@60095 0039d316-1c4b-4281-b951-d872f2087c98
TranslateManager::TranslateManager()
    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
      translate_script_expiration_delay_(kTranslateScriptExpirationDelayMS),
      translate_script_request_pending_(false) {
  notification_registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
                              NotificationService::AllSources());
  notification_registrar_.Add(this, NotificationType::TAB_LANGUAGE_DETERMINED,
                              NotificationService::AllSources());
  notification_registrar_.Add(this, NotificationType::PAGE_TRANSLATED,
                              NotificationService::AllSources());
}

TranslateManager::TranslateManager()
    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
      translate_script_expiration_delay_(kTranslateScriptExpirationDelayMS),
      translate_script_request_pending_(false) {
  notification_registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
                              NotificationService::AllSources());
  notification_registrar_.Add(this, NotificationType::TAB_LANGUAGE_DETERMINED,
                              NotificationService::AllSources());
  notification_registrar_.Add(this, NotificationType::PAGE_TRANSLATED,
                              NotificationService::AllSources());
}
