[DevTools] Turn starting tracing into promise.

third_party/WebKit/Source/devtools/front_end/sdk/TargetManager.js

 /*
  * Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * @unrestricted
  */
 SDK.TargetManager = class extends Common.Object {
@@ skipping 361 matching lines @@
   }
 
   /**
    * @return {?SDK.Target}
    */
   mainTarget() {
     return this._targets[0] || null;
   }
 
   /**
-   * @param {!SDK.Target} target
-   */
-  suspendReload(target) {
-    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(target);
-    if (resourceTreeModel)
-      resourceTreeModel.suspendReload();
-  }
-
-  /**
-   * @param {!SDK.Target} target
-   */
-  resumeReload(target) {
-    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(target);
-    if (resourceTreeModel)
-      setImmediate(resourceTreeModel.resumeReload.bind(resourceTreeModel));
-  }
-
-  /**
    * @param {function()} webSocketConnectionLostCallback
    */
   connectToMainTarget(webSocketConnectionLostCallback) {
     this._webSocketConnectionLostCallback = webSocketConnectionLostCallback;
     this._connectAndCreateMainTarget();
   }
 
   _connectAndCreateMainTarget() {
     if (Runtime.queryParam('nodeFrontend')) {
       var target = new SDK.Target(
@@ skipping 93 matching lines @@
   /**
    * @param {!T} model
    */
   modelRemoved(model) {},
 };
 
 /**
  * @type {!SDK.TargetManager}
  */
 SDK.targetManager = new SDK.TargetManager();