DevTools: fix private field usage violation discovered after the compiler roll.

third_party/WebKit/Source/devtools/front_end/timeline_model/TracingLayerTree.js

 // Copyright 2016 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.
 /** @typedef {!{
         bounds: {height: number, width: number},
         children: Array.<!TimelineModel.TracingLayerPayload>,
         layer_id: number,
         position: Array.<number>,
         scroll_offset: Array.<number>,
         layer_quad: Array.<number>,
@@ skipping 37 matching lines @@
   setLayers(root, layers, paints, callback) {
     var idsToResolve = new Set();
     if (root) {
       // This is a legacy code path for compatibility, as cc is removing
       // layer tree hierarchy, this code will eventually be removed.
       this._extractNodeIdsToResolve(idsToResolve, {}, root);
     } else {
       for (var i = 0; i < layers.length; ++i)
         this._extractNodeIdsToResolve(idsToResolve, {}, layers[i]);
     }
-    this._resolveBackendNodeIds(idsToResolve, onBackendNodeIdsResolved.bind(this));
+    this.resolveBackendNodeIds(idsToResolve, onBackendNodeIdsResolved.bind(this));
 
     /**
      * @this {TimelineModel.TracingLayerTree}
      */
     function onBackendNodeIdsResolved() {
       var oldLayersById = this._layersById;
       this._layersById = {};
       this.setContentRoot(null);
       if (root) {
         var convertedLayers = this._innerSetLayers(oldLayersById, root);
@@ skipping 56 matching lines @@
    * @return {!TimelineModel.TracingLayer}
    */
   _innerSetLayers(oldLayersById, payload) {
     var layer = /** @type {?TimelineModel.TracingLayer} */ (oldLayersById[payload.layer_id]);
     if (layer)
       layer._reset(payload);
     else
       layer = new TimelineModel.TracingLayer(this.target(), payload);
     this._layersById[payload.layer_id] = layer;
     if (payload.owner_node)
-      layer._setNode(this._backendNodeIdToNode.get(payload.owner_node) || null);
+      layer._setNode(this.backendNodeIdToNode().get(payload.owner_node) || null);
     if (!this.contentRoot() && layer.drawsContent())
       this.setContentRoot(layer);
     for (var i = 0; payload.children && i < payload.children.length; ++i)
       layer.addChild(this._innerSetLayers(oldLayersById, payload.children[i]));
     return layer;
   }
 
   /**
    * @param {!Set<number>} nodeIdsToResolve
    * @param {!Object} seenNodeIds
    * @param {!TimelineModel.TracingLayerPayload} payload
    */
   _extractNodeIdsToResolve(nodeIdsToResolve, seenNodeIds, payload) {
     var backendNodeId = payload.owner_node;
-    if (backendNodeId && !this._backendNodeIdToNode.has(backendNodeId))
+    if (backendNodeId && !this.backendNodeIdToNode().has(backendNodeId))
       nodeIdsToResolve.add(backendNodeId);
     for (var i = 0; payload.children && i < payload.children.length; ++i)
       this._extractNodeIdsToResolve(nodeIdsToResolve, seenNodeIds, payload.children[i]);
   }
 };
 
 /**
  * @implements {SDK.Layer}
  * @unrestricted
  */
@@ skipping 307 matching lines @@
   }
 
   /**
    * @override
    * @return {boolean}
    */
   drawsContent() {
     return this._drawsContent;
   }
 };