diff --git a/core/components/component.js b/core/components/component.js
index 3f893623e..ae10a207a 100644
--- a/core/components/component.js
+++ b/core/components/component.js
@@ -96,13 +96,6 @@ Blockly.Component = function() {
 };
 
 
-/**
- * Generator for unique IDs.
- * @type {!Blockly.utils.IdGenerator}
- * @private
- */
-Blockly.Component.prototype.idGenerator_ = Blockly.utils.IdGenerator.getInstance();
-
 /**
  * The default right to left value.
  * @type {?boolean}
@@ -171,27 +164,7 @@ Blockly.Component.setDefaultRightToLeft = function(rightToLeft) {
  * @package
  */
 Blockly.Component.prototype.getId = function() {
-  return this.id_ || (this.id_ = this.idGenerator_.getNextUniqueId());
-};
-
-/**
- * Assigns an ID to this component instance.  It is the caller's responsibility
- * to guarantee that the ID is unique.  If the component is a child of a parent
- * component, then the parent component's child index is updated to reflect the
- * new ID; this may throw an error if the parent already has a child with an ID
- * that conflicts with the new ID.
- * @param {string} id Unique component ID.
- * @protected
- */
-Blockly.Component.prototype.setId = function(id) {
-  if (this.parent_ && this.parent_.childIndex_) {
-    // Update the parent's child index.
-    delete this.parent_.childIndex_[this.id_];
-    this.parent_.childIndex_[id] = this;
-  }
-
-  // Update the component ID.
-  this.id_ = id;
+  return this.id_ || (this.id_ = Blockly.utils.IdGenerator.getNextUniqueId());
 };
 
 /**
diff --git a/core/components/menu/menu.js b/core/components/menu/menu.js
index 8e969eb72..bbd53ff2e 100644
--- a/core/components/menu/menu.js
+++ b/core/components/menu/menu.js
@@ -267,14 +267,8 @@ Blockly.Menu.prototype.setHighlightedIndex = function(index) {
   if (child) {
     child.setHighlighted(true);
     this.highlightedIndex_ = index;
-    if (this.highlightHandler_) {
-      this.highlightHandler_(child);
-    }
   } else if (this.highlightedIndex_ > -1) {
     this.getHighlighted().setHighlighted(false);
-    if (this.highlightHandler_) {
-      this.highlightHandler_();
-    }
     this.highlightedIndex_ = -1;
   }
 
@@ -359,15 +353,6 @@ Blockly.Menu.prototype.canHighlightItem = function(item) {
   return item.isEnabled();
 };
 
-/**
- * Set the handler that's triggered when a menuitem is highlighted.
- * @param {function(?Blockly.MenuItem)} fn The handler.
- * @package
- */
-Blockly.Menu.prototype.onHighlighted = function(fn) {
-  this.highlightHandler_ = fn;
-};
-
 // Mouse events.
 
 /**
diff --git a/core/field_colour.js b/core/field_colour.js
index 49c1d4f6e..3d13fea07 100644
--- a/core/field_colour.js
+++ b/core/field_colour.js
@@ -534,7 +534,6 @@ Blockly.FieldColour.prototype.dropdownCreate_ = function() {
       Math.floor(colours.length / columns));
   Blockly.utils.aria.setState(table, 'colcount', columns);
   var row;
-  var idGenerator = Blockly.utils.IdGenerator.getInstance();
   for (var i = 0; i < colours.length; i++) {
     if (i % columns == 0) {
       row = document.createElement('tr');
@@ -545,7 +544,7 @@ Blockly.FieldColour.prototype.dropdownCreate_ = function() {
     row.appendChild(cell);
     cell.label = colours[i];  // This becomes the value, if clicked.
     cell.title = titles[i] || colours[i];
-    cell.id = idGenerator.getNextUniqueId();
+    cell.id = Blockly.utils.IdGenerator.getNextUniqueId();
     cell.setAttribute('data-index', i);
     Blockly.utils.aria.setRole(cell, Blockly.utils.aria.Role.GRIDCELL);
     Blockly.utils.aria.setState(cell,
diff --git a/core/utils/idgenerator.js b/core/utils/idgenerator.js
index 71a02b976..3b99df9c6 100644
--- a/core/utils/idgenerator.js
+++ b/core/utils/idgenerator.js
@@ -29,38 +29,19 @@
 goog.provide('Blockly.utils.IdGenerator');
 
 
-/**
- * Creates a new ID generator.
- * @constructor
- * @final
- */
-Blockly.utils.IdGenerator = function() {};
-
-/**
- * Get the singleton instance of Blockly.utils.IdGenerator.
- * @return {Blockly.utils.IdGenerator} singleton instance
- */
-Blockly.utils.IdGenerator.getInstance = function() {
-  if (!Blockly.utils.IdGenerator.instance_) {
-    Blockly.utils.IdGenerator.instance_ = new Blockly.utils.IdGenerator();
-  }
-  return Blockly.utils.IdGenerator.instance_;
-};
-
 /**
  * Next unique ID to use.
  * @type {number}
  * @private
  */
-Blockly.utils.IdGenerator.prototype.nextId_ = 0;
+Blockly.utils.IdGenerator.nextId_ = 0;
 
 /**
  * Gets the next unique ID.
- * The difference between this and genUid is that getNextUniqueId generates
- * IDs compatible with the HTML4 id attribute restrictions:
+ * IDs are compatible with the HTML4 id attribute restrictions:
  * Use only ASCII letters, digits, '_', '-' and '.'
  * @return {string} The next unique identifier.
  */
-Blockly.utils.IdGenerator.prototype.getNextUniqueId = function() {
-  return 'blockly:' + (this.nextId_++).toString(36);
+Blockly.utils.IdGenerator.getNextUniqueId = function() {
+  return 'blockly:' + (Blockly.utils.IdGenerator.nextId_++).toString(36);
 };