[CLEANUP] Remove sync queue from @ember/runloop.

packages/@ember/deprecated-features/index.ts

@@ -5,7 +5,6 @@
 
 export const SEND_ACTION = !!'3.4.0';
 export const EMBER_EXTEND_PROTOTYPES = !!'3.2.0-beta.5';
-export const RUN_SYNC = !!'3.0.0-beta.4';
 export const LOGGER = !!'3.2.0-beta.1';
 export const MERGE = !!'3.6.0-beta.1';
 export const ROUTER_EVENTS = !!'4.0.0';

packages/@ember/runloop/index.js

@@ -1,8 +1,6 @@
-import { assert, deprecate } from '@ember/debug';
+import { assert } from '@ember/debug';
 import { onErrorTarget } from '@ember/-internals/error-handling';
-import { beginPropertyChanges, endPropertyChanges } from '@ember/-internals/metal';
 import Backburner from 'backburner';
-import { RUN_SYNC } from '@ember/deprecated-features';
 
 let currentRunLoop = null;
 export function getCurrentRunLoop() {
@@ -46,24 +44,13 @@ export const queues = [
   _rsvpErrorQueue,
 ];
 
-let backburnerOptions = {
+export const backburner = new Backburner(queues, {
   defaultQueue: 'actions',
   onBegin,
   onEnd,
   onErrorTarget,
   onErrorMethod: 'onerror',
-};
-
-if (RUN_SYNC) {
-  queues.unshift('sync');
-
-  backburnerOptions.sync = {
-    before: beginPropertyChanges,
-    after: endPropertyChanges,
-  };
-}
-
-export const backburner = new Backburner(queues, backburnerOptions);
+});
 
 /**
  @module @ember/runloop
@@ -324,12 +311,7 @@ export function end() {
   @return {*} Timer information for use in canceling, see `cancel`.
   @public
 */
-export function schedule(queue /*, target, method */) {
-  deprecate(`Scheduling into the '${queue}' run loop queue is deprecated.`, queue !== 'sync', {
-    id: 'ember-metal.run.sync',
-    until: '3.5.0',
-  });
-
+export function schedule(/* queue, target, method */) {
   return backburner.schedule(...arguments);
 }
 
@@ -469,11 +451,7 @@ export function once(...args) {
   @return {Object} Timer information for use in canceling, see `cancel`.
   @public
 */
-export function scheduleOnce(queue /*, target, method*/) {
-  deprecate(`Scheduling into the '${queue}' run loop queue is deprecated.`, queue !== 'sync', {
-    id: 'ember-metal.run.sync',
-    until: '3.5.0',
-  });
+export function scheduleOnce(/* queue, target, method*/) {
   return backburner.scheduleOnce(...arguments);
 }
 

packages/@ember/runloop/tests/schedule_test.js

@@ -50,28 +50,24 @@ moduleFor(
         let runLoop = getCurrentRunLoop();
         assert.ok(runLoop, 'run loop present');
 
-        expectDeprecation(() => {
-          schedule('sync', () => {
-            order.push('sync');
-            assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
-          });
-        }, `Scheduling into the 'sync' run loop queue is deprecated.`);
-
         schedule('actions', () => {
           order.push('actions');
           assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
+        });
+
+        schedule('afterRender', () => {
+          order.push('afterRender');
+          assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
+
+          schedule('afterRender', () => {
+            order.push('afterRender');
+            assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
+          });
 
           schedule('actions', () => {
             order.push('actions');
             assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
           });
-
-          expectDeprecation(() => {
-            schedule('sync', () => {
-              order.push('sync');
-              assert.equal(runLoop, getCurrentRunLoop(), 'same run loop used');
-            });
-          }, `Scheduling into the 'sync' run loop queue is deprecated.`);
         });
 
         schedule('destroy', () => {
@@ -80,7 +76,7 @@ moduleFor(
         });
       });
 
-      assert.deepEqual(order, ['sync', 'actions', 'sync', 'actions', 'destroy']);
+      assert.deepEqual(order, ['actions', 'afterRender', 'actions', 'afterRender', 'destroy']);
     }
   }
 );