--- a/browser/components/customizableui/src/CustomizableUI.jsm
+++ b/browser/components/customizableui/src/CustomizableUI.jsm
@@ -2142,18 +2142,16 @@ this.CustomizableUI = {
    */
   get SOURCE_BUILTIN() "builtin",
   /**
    * Constant indicating the widget is externally provided
    * (e.g. by add-ons or other items not part of the builtin widget set).
    */
   get SOURCE_EXTERNAL() "external",
 
-  get TYPE_BUTTON() "button",
-
   /**
    * The class used to distinguish items that span the entire menu panel.
    */
   get WIDE_PANEL_CLASS() "panel-wide-item",
   /**
    * The (constant) number of columns in the menu panel.
    */
   get PANEL_COLUMN_COUNT() 3,
@@ -2724,17 +2722,19 @@ this.CustomizableUI = {
    * @param aArea     the area ID you want to move it to.
    * @return true if this is possible, false if it is not. Same caveats as
    *              for isWidgetRemovable apply, however, if no windows are open.
    */
   canWidgetMoveToArea: function(aWidgetId, aArea) {
     return CustomizableUIInternal.canWidgetMoveToArea(aWidgetId, aArea);
   },
   /**
-   * Whether we're in a default state.
+   * Whether we're in a default state. Note that non-removable non-default
+   * widgets and non-existing widgets are not taken into account in determining
+   * whether we're in the default state.
    *
    * NB: this is a property with a getter. The getter is NOT cheap, because
    * it does smart things with non-removable non-default items, non-existent
    * items, and so forth. Please don't call unless necessary.
    */
   get inDefaultState() {
     return CustomizableUIInternal.inDefaultState;
   },