DevTools: Add icons to performance pane tabs.

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

Index: third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js b/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
index a9de61fd29b0ed10fc1916648bd85460613a369f..295a7fd596650b7b63a1b96dbd9839e74adbedcd 100644
--- a/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
+++ b/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
@@ -118,6 +118,10 @@ Timeline.TimelinePanel = class extends UI.Panel {
       this._tabbedPane.appendTab(viewMode.BottomUp, Common.UIString('Bottom-Up'), new UI.VBox());
       this._tabbedPane.appendTab(viewMode.CallTree, Common.UIString('Call Tree'), new UI.VBox());
       this._tabbedPane.appendTab(viewMode.EventLog, Common.UIString('Event Log'), new UI.VBox());
+      this._tabbedPane.setTabIcon(viewMode.FlameChart, UI.Icon.create('largeicon-perf-flamechart'));
+      this._tabbedPane.setTabIcon(viewMode.BottomUp, UI.Icon.create('largeicon-perf-bottom-up-tree'));
+      this._tabbedPane.setTabIcon(viewMode.CallTree, UI.Icon.create('largeicon-perf-call-tree'));
+      this._tabbedPane.setTabIcon(viewMode.EventLog, UI.Icon.create('largeicon-perf-event-list'));
       this._tabbedPane.addEventListener(UI.TabbedPane.Events.TabSelected, this._onMainViewChanged.bind(this));
       this._tabbedPane.selectTab(this._viewModeSetting.get());
     } else {
@@ -139,9 +143,6 @@ Timeline.TimelinePanel = class extends UI.Panel {
     Extensions.extensionServer.addEventListener(
         Extensions.ExtensionServer.Events.TraceProviderAdded, this._appendExtensionsToToolbar, this);
     SDK.targetManager.addEventListener(SDK.TargetManager.Events.SuspendStateChanged, this._onSuspendStateChanged, this);
-
-    /** @type {!SDK.TracingModel.Event}|undefined */
-    this._selectedSearchResult;
   }
 
   /**