Bug 1451024 - Cookie settings should be disabled when the related prefs are locked r=jaws

MozReview-Commit-ID: DR0e8fFBNDj

--HG--
extra : rebase_source : a1a440b674ec6b3089357fe6048407440182045e

browser/components/preferences/in-content/privacy.js

@@ -839,23 +839,30 @@ var gPrivacyPane = {
 
   /**
    * Reads the network.cookie.cookieBehavior preference value and
-   * enables/disables the rest of the cookie UI accordingly, returning true
-   * if cookies are enabled.
+   * disables parts of the cookie UI if appropriate.
+   *
+   * Returns "0" if cookies are accepted and "2" if they are entirely disabled.
    */
   readAcceptCookies() {
-    var pref = Preferences.get("network.cookie.cookieBehavior");
-    var acceptThirdPartyLabel = document.getElementById("acceptThirdPartyLabel");
-    var acceptThirdPartyMenu = document.getElementById("acceptThirdPartyMenu");
-    var keepUntil = document.getElementById("keepUntil");
-    var menu = document.getElementById("keepCookiesUntil");
+    let pref = Preferences.get("network.cookie.cookieBehavior");
+    let acceptThirdPartyLabel = document.getElementById("acceptThirdPartyLabel");
+    let acceptThirdPartyMenu = document.getElementById("acceptThirdPartyMenu");
+    let keepUntilLabel = document.getElementById("keepUntil");
+    let keepUntilMenu = document.getElementById("keepCookiesUntil");
 
     // enable the rest of the UI for anything other than "disable all cookies"
-    var acceptCookies = (pref.value != 2);
+    let acceptCookies = (pref.value != 2);
 
-    acceptThirdPartyLabel.disabled = acceptThirdPartyMenu.disabled = !acceptCookies;
+    if (!acceptThirdPartyMenu.disabled) {
+      acceptThirdPartyMenu.disabled = !acceptCookies;
+    }
+    acceptThirdPartyLabel.disabled = acceptThirdPartyMenu.disabled;
 
     let privateBrowsing = Preferences.get("browser.privatebrowsing.autostart").value;
-    keepUntil.disabled = menu.disabled = privateBrowsing || !acceptCookies;
+    if (!keepUntilMenu.disabled) {
+      keepUntilMenu.disabled = privateBrowsing || !acceptCookies;
+    }
+    keepUntilLabel.disabled = keepUntilMenu.disabled;
 
     // Our top-level setting is a radiogroup that only sets "enable all"
     // and "disable all", so convert the pref value accordingly.