DevTools: render console level filter as drop box.

third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2011 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 91 matching lines @@
     if (this._proxyElement)
       throw 'Cannot attach an attached TextPrompt';
     this._element = element;
 
     this._boundOnKeyDown = this.onKeyDown.bind(this);
     this._boundOnInput = this.onInput.bind(this);
     this._boundOnMouseWheel = this.onMouseWheel.bind(this);
     this._boundClearAutocomplete = this.clearAutocomplete.bind(this);
     this._proxyElement = element.ownerDocument.createElement('span');
     var shadowRoot = UI.createShadowRootWithCoreStyles(this._proxyElement, 'ui/textPrompt.css');
-    this._contentElement = shadowRoot.createChild('div');
+    this._contentElement = shadowRoot.createChild('div', 'text-prompt-root');
     this._contentElement.createChild('content');
     this._proxyElement.style.display = this._proxyElementDisplay;
     element.parentElement.insertBefore(this._proxyElement, element);
     this._proxyElement.appendChild(element);
     this._element.classList.add('text-prompt');
     this._element.addEventListener('keydown', this._boundOnKeyDown, false);
     this._element.addEventListener('input', this._boundOnInput, false);
     this._element.addEventListener('mousewheel', this._boundOnMouseWheel, false);
     this._element.addEventListener('selectstart', this._boundClearAutocomplete, false);
     this._element.addEventListener('blur', this._boundClearAutocomplete, false);
@@ skipping 513 matching lines @@
   }
 };
 
 UI.TextPrompt.DefaultAutocompletionTimeout = 250;
 
 /** @enum {symbol} */
 UI.TextPrompt.Events = {
   ItemApplied: Symbol('text-prompt-item-applied'),
   ItemAccepted: Symbol('text-prompt-item-accepted')
 };