DevTools: Do not show network pane on Timeline when there're no network activity

third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.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.
 
 Timeline.FlameChartStyle = {
   textColor: '#333'
 };
 
 /**
  * @enum {symbol}
@@ skipping 176 matching lines @@
   /**
    * @override
    */
   refreshRecords() {
     this._dataProvider.reset();
     this._nextExtensionIndex = 0;
     this.extensionDataAdded();
     this._mainView.scheduleUpdate();
 
     this._networkDataProvider.reset();
+    if (this._networkDataProvider.isEmpty()) {
+        this._mainView.enableRuler(true);
+        this._splitWidget.hideSidebar();
+    } else {
+        this._mainView.enableRuler(false);
+        this._splitWidget.showBoth();
+        this.resizeToPreferredHeights();
+    }
     this._networkView.scheduleUpdate();
   }
 
   /**
    * @override
    */
   extensionDataAdded() {
     while (this._nextExtensionIndex < this._extensionModels.length)
       this._dataProvider.appendExtensionEvents(this._extensionModels[this._nextExtensionIndex++]);
     this._mainView.scheduleUpdate();
@@ skipping 81 matching lines @@
   /**
    * @param {!UI.FlameChartDataProvider} dataProvider
    * @param {!Common.Event} event
    */
   _onEntrySelected(dataProvider, event) {
     var entryIndex = /** @type{number} */ (event.data);
     this._delegate.select(dataProvider.createSelection(entryIndex));
   }
 
   resizeToPreferredHeights() {
-    this._splitWidget.setSidebarSize(this._networkDataProvider.preferredHeight() + this._splitResizer.clientHeight);
+    this._splitWidget.setSidebarSize(
+        this._networkDataProvider.preferredHeight() + this._splitResizer.clientHeight + UI.FlameChart.HeaderHeight + 2);
   }
 };
 
 /**
  * @unrestricted
  */
 Timeline.TimelineFlameChartView.Selection = class {
   /**
    * @param {!Timeline.TimelineSelection} selection
    * @param {number} entryIndex
    */
   constructor(selection, entryIndex) {
     this.timelineSelection = selection;
     this.entryIndex = entryIndex;
   }
 };