Timeline: fix NPE in heavy stack view when clearing Timeline

third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js

Index: third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js
index 01a9b47a7a6cb838e07c8ee44416a67d94ef4235..d0f130546714584b869a3e9d7c7229dc9aecfd0c 100644
--- a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js
+++ b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartView.js
@@ -115,20 +115,19 @@ Timeline.TimelineFlameChartView = class extends UI.VBox {
     this._model = model;
     if (this._model)
       this._model.addEventListener(extensionDataAdded, this._appendExtensionData, this);
-    this._updateSearchHighlight(false, true);
-    this._refresh();
-  }
-
-  _refresh() {
     this._mainDataProvider.setModel(this._model);
     this._networkDataProvider.setModel(this._model);
     this._countersView.setModel(this._model);
-    if (this._detailsView)
-      this._detailsView.setModel(this._model);
+    this._detailsView.setModel(this._model);
 
     this._nextExtensionIndex = 0;
     this._appendExtensionData();
 
+    this._updateSearchHighlight(false, true);
+    this._refresh();
+  }
+
+  _refresh() {
     if (this._networkDataProvider.isEmpty()) {
       this._mainFlameChart.enableRuler(true);
       this._networkSplitWidget.hideSidebar();