DevTools: enable private field checks as a part of compilation.

third_party/WebKit/Source/devtools/front_end/timeline/TimelineNetworkFlameChart.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.
 
 /**
  * @unrestricted
  */
 Timeline.TimelineFlameChartNetworkDataProvider = class extends Timeline.TimelineFlameChartDataProviderBase {
   /**
    * @param {!TimelineModel.TimelineModel} model
    */
   constructor(model) {
     super();
     this._model = model;
     /** @type {?UI.FlameChart.TimelineData} */
     this._timelineData = null;
     var loadingCategory = Timeline.TimelineUIUtils.categories()['loading'];
     this._waitingColor = loadingCategory.childColor;
     this._processingColor = loadingCategory.color;
 
     this._style = {
       padding: 4,
       height: 17,
       collapsible: true,
       color: UI.themeSupport.patchColor('#222', UI.ThemeSupport.ColorUsage.Foreground),
-      font: this._font,
+      font: this.font(),
       backgroundColor: UI.themeSupport.patchColor('white', UI.ThemeSupport.ColorUsage.Background),
       nestingLevel: 0,
       useFirstLineForOverview: false,
       shareHeaderLine: false
     };
     this._group = {startLevel: 0, name: Common.UIString('Network'), expanded: true, style: this._style};
   }
 
   /**
    * @override
@@ skipping 279 matching lines @@
     this._timelineData.entryLevels.push(this._requests.length - 1);
   }
 
   /**
    * @return {number}
    */
   preferredHeight() {
     return this._style.height * (this._group.expanded ? Number.constrain(this._currentLevel + 1, 4, 8) : 2) + 2;
   }
 };