Bug 1453517 - Consolidate popup permission checks to nsContentUtils; r=bz

Permissions checks for popups were happening in nsIPopupWindowManager,
but that really only required a pref and perm check. The XPCOM
machinery around this isn't really needed, and the check was only
called from two places in content, so this fits in nsContentUtils.

MozReview-Commit-ID: 9x60x1BKWcr

dom/html/HTMLInputElement.cpp

@@ -695,14 +695,7 @@ HTMLInputElement::IsPopupBlocked() const
     return false;
   }
 
-  nsCOMPtr<nsIPopupWindowManager> pm = do_GetService(NS_POPUPWINDOWMANAGER_CONTRACTID);
-  if (!pm) {
-    return true;
-  }
-
-  uint32_t permission;
-  pm->TestPermission(OwnerDoc()->NodePrincipal(), &permission);
-  return permission == nsIPopupWindowManager::DENY_POPUP;
+  return !nsContentUtils::CanShowPopup(OwnerDoc()->NodePrincipal());
 }
 
 nsresult