DevTools: move DOMExtension.js into ui module.

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

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * 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:
  *
@@ skipping 1998 matching lines @@
   return new Promise(fulfill => {
     var image = new Image();
     image.addEventListener('load', () => fulfill(image));
     image.addEventListener('error', () => fulfill(null));
     image.src = url;
   });
 };
 
 /** @type {!UI.ThemeSupport} */
 UI.themeSupport;
+
+/**
+ * @param {function(!File)} callback
+ * @return {!Node}
+ */
+UI.createFileSelectorElement = function(callback) {
+  var fileSelectorElement = createElement('input');
+  fileSelectorElement.type = 'file';
+  fileSelectorElement.style.display = 'none';
+  fileSelectorElement.setAttribute('tabindex', -1);
+  fileSelectorElement.onchange = onChange;
+  function onChange(event) {
+    callback(fileSelectorElement.files[0]);
+  }
+  return fileSelectorElement;
+};