[DevTools] Separate ScreenCaptureModel out of ResourceTreeModel.

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

 /*
  * Copyright 2014 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.
  */
 
 /**
  * @unrestricted
  */
 SDK.TargetManager = class extends Common.Object {
@@ skipping 398 matching lines @@
     if (Runtime.queryParam('nodeFrontend')) {
       var target = new SDK.Target(
           this, Common.UIString('Node'), SDK.Target.Capability.Target, this._createMainConnection.bind(this), null);
       target.subTargetsManager = new SDK.SubTargetsManager(target);
       target.setInspectedURL('Node');
       Host.userMetrics.actionTaken(Host.UserMetrics.Action.ConnectToNodeJSFromFrontend);
       return;
     }
 
     var capabilities = SDK.Target.Capability.Browser | SDK.Target.Capability.DOM | SDK.Target.Capability.JS |
-        SDK.Target.Capability.Log | SDK.Target.Capability.Network | SDK.Target.Capability.Target;
+        SDK.Target.Capability.Log | SDK.Target.Capability.Network | SDK.Target.Capability.Target |
+        SDK.Target.Capability.ScreenCapture;
     if (Runtime.queryParam('isSharedWorker')) {
       capabilities = SDK.Target.Capability.Browser | SDK.Target.Capability.Log | SDK.Target.Capability.Network |
           SDK.Target.Capability.Target;
     } else if (Runtime.queryParam('v8only')) {
       capabilities = SDK.Target.Capability.JS;
       Host.userMetrics.actionTaken(Host.UserMetrics.Action.ConnectToNodeJSDirectly);
     }
 
     var target = this.createTarget(Common.UIString('Main'), capabilities, this._createMainConnection.bind(this), null);
     target.runtimeAgent().runIfWaitingForDebugger();
@@ skipping 71 matching lines @@
   /**
    * @param {!T} model
    */
   modelRemoved(model) {},
 };
 
 /**
  * @type {!SDK.TargetManager}
  */
 SDK.targetManager = new SDK.TargetManager();