Emit a console warning when blocking event listener is delayed for too long

third_party/WebKit/Source/devtools/front_end/main/Main.js

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2007 Matt Lilek (pewtermoose@gmail.com).
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 1038 matching lines @@
 /**
  * @constructor
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.BackendSettingsSync = function()
 {
     this._autoAttachSetting = WebInspector.settings.moduleSetting("autoAttachToCreatedPages");
     this._autoAttachSetting.addChangeListener(this._update, this);
     this._disableJavascriptSetting = WebInspector.settings.moduleSetting("javaScriptDisabled");
     this._disableJavascriptSetting.addChangeListener(this._update, this);
+    this._blockedEventsWarningSetting = WebInspector.settings.moduleSetting("blockedEventsWarningEnabled");
+    this._blockedEventsWarningSetting.addChangeListener(this._update, this);
     WebInspector.targetManager.observeTargets(this, WebInspector.Target.Type.Page);
 }
 
 WebInspector.BackendSettingsSync.prototype = {
+    /**
+     * @param {!WebInspector.Target} target
+     */
+    _updateTarget: function(target)
+    {
+        var blockedEventsWarningThresholdSeconds = 0.1;
+        target.pageAgent().setBlockedEventsWarningThreshold(this._blockedEventsWarningSetting.get() ? blockedEventsWarningThresholdSeconds : 0);
+        target.pageAgent().setAutoAttachToCreatedPages(this._autoAttachSetting.get());
+        target.emulationAgent().setScriptExecutionDisabled(this._disableJavascriptSetting.get());
+    },
+
     _update: function()
     {
-        for (var target of WebInspector.targetManager.targets(WebInspector.Target.Type.Page)) {
-            target.pageAgent().setAutoAttachToCreatedPages(this._autoAttachSetting.get());
-            target.emulationAgent().setScriptExecutionDisabled(this._disableJavascriptSetting.get());
-        }
+        WebInspector.targetManager.targets(WebInspector.Target.Type.Page).forEach(this._updateTarget, this);
     },
 
     /**
      * @param {!WebInspector.Target} target
      * @override
      */
     targetAdded: function(target)
     {
-        target.pageAgent().setAutoAttachToCreatedPages(this._autoAttachSetting.get());
-        target.emulationAgent().setScriptExecutionDisabled(this._disableJavascriptSetting.get());
+        this._updateTarget(target);
         target.renderingAgent().setShowViewportSizeOnResize(true);
     },
 
     /**
      * @param {!WebInspector.Target} target
      * @override
      */
     targetRemoved: function(target)
     {
     }
@@ skipping 13 matching lines @@
      * @return {?Element}
      */
     settingElement: function()
     {
         return WebInspector.SettingsUI.createSettingCheckbox(WebInspector.UIString("Show rulers"), WebInspector.moduleSetting("showMetricsRulers"));
     }
 }
 
 
 new WebInspector.Main();