[DevTools] Turn ConsoleModel into a singleton

third_party/WebKit/Source/devtools/front_end/sdk/LogModel.js

 // Copyright 2017 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.
 
 /**
  * @implements {Protocol.LogDispatcher}
  */
 SDK.LogModel = class extends SDK.SDKModel {
   /**
    * @param {!SDK.Target} target
@@ skipping 10 matching lines @@
         {name: 'recurringHandler', threshold: 50}, {name: 'discouragedAPIUse', threshold: -1}
       ]);
     }
   }
 
   /**
    * @override
    * @param {!Protocol.Log.LogEntry} payload
    */
   entryAdded(payload) {
-    this.emit(new SDK.LogModel.EntryAddedEvent(payload));
+    this.emit(new SDK.LogModel.EntryAddedEvent(this, payload));
   }
 
   requestClear() {
     this._logAgent.clear();
   }
 };
 
 SDK.SDKModel.register(SDK.LogModel, SDK.Target.Capability.Log);
 
 /** @implements {Common.Emittable} */
 SDK.LogModel.EntryAddedEvent = class {
   /**
+   * @param {!SDK.LogModel} logModel
    * @param {!Protocol.Log.LogEntry} entry
    */
-  constructor(entry) {
+  constructor(logModel, entry) {
+    this.logModel = logModel;
     this.entry = entry;
   }
 };