[DevTools] Do not expose agents on Target

third_party/WebKit/Source/devtools/front_end/sdk/ScreenCaptureModel.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.PageDispatcher}
  */
 SDK.ScreenCaptureModel = class extends SDK.SDKModel {
   /**
    * @param {!SDK.Target} target
+   * @param {!Protocol.Dispatcher} dispatcher
    */
-  constructor(target) {
-    super(target);
-    this._agent = target.pageAgent();
+  constructor(target, dispatcher) {
+    super(target, dispatcher);
+    this._agent = dispatcher.pageAgent();
     /** @type {?function(string, !Protocol.Page.ScreencastFrameMetadata)} */
     this._onScreencastFrame = null;
     /** @type {?function(boolean)} */
     this._onScreencastVisibilityChanged = null;
-    target.registerPageDispatcher(this);
+    dispatcher.registerPageDispatcher(this);
   }
 
   /**
    * @param {string} format
    * @param {number} quality
    * @param {number|undefined} width
    * @param {number|undefined} height
    * @param {number|undefined} everyNthFrame
    * @param {function(string, !Protocol.Page.ScreencastFrameMetadata)} onFrame
    * @param {function(boolean)} onVisibilityChanged
@@ skipping 164 matching lines @@
   }
 
   /**
    * @override
    */
   navigationRequested() {
   }
 };
 
 SDK.SDKModel.register(SDK.ScreenCaptureModel, SDK.Target.Capability.ScreenCapture, false);