DevTools: bring back old landing page in timeline/performance.

third_party/WebKit/Source/devtools/front_end/extensions/ExtensionServer.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 559 matching lines @@
 
   /**
    * @param {!Object} message
    * @param {!MessagePort} port
    */
   _onAddTraceProvider(message, port) {
     var provider = new Extensions.ExtensionTraceProvider(
         port._extensionOrigin, message.id, message.categoryName, message.categoryTooltip);
     this._clientObjects[message.id] = provider;
     this._traceProviders.push(provider);
-    this.dispatchEventToListeners(Extensions.ExtensionServer.Events.TraceProviderAdded);
+    this.dispatchEventToListeners(Extensions.ExtensionServer.Events.TraceProviderAdded, provider);
   }
 
   /**
    * @return {!Array<!Extensions.ExtensionTraceProvider>}
    */
   traceProviders() {
     return this._traceProviders;
   }
 
   /**
@@ skipping 461 matching lines @@
 /**
  * @typedef {{code: string, description: string, details: !Array.<*>}}
  */
 Extensions.ExtensionStatus.Record;
 
 Extensions.extensionAPI = {};
 defineCommonExtensionSymbols(Extensions.extensionAPI);
 
 /** @type {!Extensions.ExtensionServer} */
 Extensions.extensionServer;