DevTools: make flame chart a web component.

Source/devtools/front_end/components/HelpScreen.js

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
     this.registerRequiredCSS("components/helpScreen.css");
 
     this.element.classList.add("help-window-outer");
     this.element.addEventListener("keydown", this._onKeyDown.bind(this), false);
     this.element.tabIndex = 0;
 
     if (title) {
         var mainWindow = this.element.createChild("div", "help-window-main");
         var captionWindow = mainWindow.createChild("div", "help-window-caption");
         captionWindow.appendChild(this._createCloseButton());
-        this.contentElement = mainWindow.createChild("div", "help-content");
+        this.helpContentElement = mainWindow.createChild("div", "help-content");
         captionWindow.createChild("h1", "help-window-title").textContent = title;
     }
 }
 
 /**
  * @type {?WebInspector.HelpScreen}
  */
 WebInspector.HelpScreen._visibleScreen = null;
 
 WebInspector.HelpScreen.prototype = {
@@ skipping 55 matching lines @@
     __proto__: WebInspector.VBox.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.HelpScreen}
  */
 WebInspector.RemoteDebuggingTerminatedScreen = function(reason)
 {
     WebInspector.HelpScreen.call(this, WebInspector.UIString("Detached from the target"));
-    var p = this.contentElement.createChild("p");
+    var p = this.helpContentElement.createChild("p");
     p.classList.add("help-section");
     p.createChild("span").textContent = WebInspector.UIString("Remote debugging has been terminated with reason: ");
     p.createChild("span", "error-message").textContent = reason;
     p.createChild("br");
     p.createChild("span").textContent = WebInspector.UIString("Please re-attach to the new target.");
 }
 
 WebInspector.RemoteDebuggingTerminatedScreen.prototype = {
     __proto__: WebInspector.HelpScreen.prototype
 }
 
 /**
  * @constructor
  * @extends {WebInspector.HelpScreen}
  */
 WebInspector.WorkerTerminatedScreen = function()
 {
     WebInspector.HelpScreen.call(this, WebInspector.UIString("Inspected worker terminated"));
-    var p = this.contentElement.createChild("p");
+    var p = this.helpContentElement.createChild("p");
     p.classList.add("help-section");
     p.textContent = WebInspector.UIString("Inspected worker has terminated. Once it restarts we will attach to it automatically.");
 }
 
 WebInspector.WorkerTerminatedScreen.prototype = {
 
     __proto__: WebInspector.HelpScreen.prototype
 }