Removed EventDispatched.apply() to help out with tree-shaking. See #9597.

src/Three.Legacy.js

@@ -19,7 +19,6 @@ import {
 	BufferAttribute
 } from './core/BufferAttribute.js';
 import { BufferGeometry } from './core/BufferGeometry.js';
-import { EventDispatcher } from './core/EventDispatcher.js';
 import { Face3 } from './core/Face3.js';
 import { Geometry } from './core/Geometry';
 import { Object3D } from './core/Object3D.js';
@@ -911,25 +910,6 @@ Object.defineProperties( ShaderMaterial.prototype, {
 
 //
 
-EventDispatcher.prototype = Object.assign( Object.create( {
-
-	// Note: Extra base ensures these properties are not 'assign'ed.
-
-	constructor: EventDispatcher,
-
-	apply: function ( target ) {
-
-		console.warn( "THREE.EventDispatcher: .apply is deprecated, " +
-				"just inherit or Object.assign the prototype to mix-in." );
-
-		Object.assign( target, this );
-
-	}
-
-} ), EventDispatcher.prototype );
-
-//
-
 Object.assign( WebGLRenderer.prototype, {
 
 	supportsFloatTextures: function () {