[DevTools] Do not expose agents on Target

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

Index: third_party/WebKit/Source/devtools/front_end/sdk/TracingManager.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/TracingManager.js b/third_party/WebKit/Source/devtools/front_end/sdk/TracingManager.js
index 2fc8bf73d0dba223a567028af0ceea7b56b2421c..35086590c9f3521b077bdd17c85ad0de93041326 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/TracingManager.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/TracingManager.js
@@ -30,11 +30,12 @@ SDK.TracingManagerClient.prototype = {
 SDK.TracingManager = class extends SDK.SDKModel {
   /**
    * @param {!SDK.Target} target
+   * @param {!Protocol.Dispatcher} dispatcher
    */
-  constructor(target) {
-    super(target);
-    this._tracingAgent = target.tracingAgent();
-    target.registerTracingDispatcher(new SDK.TracingDispatcher(this));
+  constructor(target, dispatcher) {
+    super(target, dispatcher);
+    this._tracingAgent = dispatcher.tracingAgent();
+    dispatcher.registerTracingDispatcher(new SDK.TracingDispatcher(this));
 
     /** @type {?SDK.TracingManagerClient} */
     this._activeClient = null;