| /* | 
 |  * Copyright (C) 2007 Apple Inc.  All rights reserved. | 
 |  * Copyright (C) 2012 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. | 
 |  * 2.  Redistributions in binary form must reproduce the above copyright | 
 |  *     notice, this list of conditions and the following disclaimer in the | 
 |  *     documentation and/or other materials provided with the distribution. | 
 |  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of | 
 |  *     its contributors may be used to endorse or promote products derived | 
 |  *     from this software without specific prior written permission. | 
 |  * | 
 |  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY | 
 |  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | 
 |  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 
 |  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY | 
 |  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | 
 |  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | 
 |  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | 
 |  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
 |  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 
 |  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
 |  * | 
 |  * Contains diff method based on Javascript Diff Algorithm By John Resig | 
 |  * http://ejohn.org/files/jsdiff.js (released under the MIT license). | 
 |  */ | 
 | /** | 
 |  * @param {number} offset | 
 |  * @param {string} stopCharacters | 
 |  * @param {!Node} stayWithinNode | 
 |  * @param {string=} direction | 
 |  * @return {!Range} | 
 |  */ | 
 | Node.prototype.rangeOfWord = function(offset, stopCharacters, stayWithinNode, direction) { | 
 |   let startNode; | 
 |   let startOffset = 0; | 
 |   let endNode; | 
 |   let endOffset = 0; | 
 |  | 
 |   if (!stayWithinNode) { | 
 |     stayWithinNode = this; | 
 |   } | 
 |  | 
 |   if (!direction || direction === 'backward' || direction === 'both') { | 
 |     let node = this; | 
 |     while (node) { | 
 |       if (node === stayWithinNode) { | 
 |         if (!startNode) { | 
 |           startNode = stayWithinNode; | 
 |         } | 
 |         break; | 
 |       } | 
 |  | 
 |       if (node.nodeType === Node.TEXT_NODE) { | 
 |         const start = (node === this ? (offset - 1) : (node.nodeValue.length - 1)); | 
 |         for (let i = start; i >= 0; --i) { | 
 |           if (stopCharacters.indexOf(node.nodeValue[i]) !== -1) { | 
 |             startNode = node; | 
 |             startOffset = i + 1; | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |  | 
 |       if (startNode) { | 
 |         break; | 
 |       } | 
 |  | 
 |       node = node.traversePreviousNode(stayWithinNode); | 
 |     } | 
 |  | 
 |     if (!startNode) { | 
 |       startNode = stayWithinNode; | 
 |       startOffset = 0; | 
 |     } | 
 |   } else { | 
 |     startNode = this; | 
 |     startOffset = offset; | 
 |   } | 
 |  | 
 |   if (!direction || direction === 'forward' || direction === 'both') { | 
 |     let node = this; | 
 |     while (node) { | 
 |       if (node === stayWithinNode) { | 
 |         if (!endNode) { | 
 |           endNode = stayWithinNode; | 
 |         } | 
 |         break; | 
 |       } | 
 |  | 
 |       if (node.nodeType === Node.TEXT_NODE) { | 
 |         const start = (node === this ? offset : 0); | 
 |         for (let i = start; i < node.nodeValue.length; ++i) { | 
 |           if (stopCharacters.indexOf(node.nodeValue[i]) !== -1) { | 
 |             endNode = node; | 
 |             endOffset = i; | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |  | 
 |       if (endNode) { | 
 |         break; | 
 |       } | 
 |  | 
 |       node = node.traverseNextNode(stayWithinNode); | 
 |     } | 
 |  | 
 |     if (!endNode) { | 
 |       endNode = stayWithinNode; | 
 |       endOffset = stayWithinNode.nodeType === Node.TEXT_NODE ? stayWithinNode.nodeValue.length : | 
 |                                                                stayWithinNode.childNodes.length; | 
 |     } | 
 |   } else { | 
 |     endNode = this; | 
 |     endOffset = offset; | 
 |   } | 
 |  | 
 |   const result = this.ownerDocument.createRange(); | 
 |   result.setStart(startNode, startOffset); | 
 |   result.setEnd(endNode, endOffset); | 
 |  | 
 |   return result; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Node=} stayWithin | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.traverseNextTextNode = function(stayWithin) { | 
 |   let node = this.traverseNextNode(stayWithin); | 
 |   if (!node) { | 
 |     return null; | 
 |   } | 
 |   const nonTextTags = {'STYLE': 1, 'SCRIPT': 1}; | 
 |   while (node && (node.nodeType !== Node.TEXT_NODE || nonTextTags[node.parentElement.nodeName])) { | 
 |     node = node.traverseNextNode(stayWithin); | 
 |   } | 
 |  | 
 |   return node; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {number|undefined} x | 
 |  * @param {number|undefined} y | 
 |  * @param {!Element=} relativeTo | 
 |  */ | 
 | Element.prototype.positionAt = function(x, y, relativeTo) { | 
 |   let shift = {x: 0, y: 0}; | 
 |   if (relativeTo) { | 
 |     shift = relativeTo.boxInWindow(this.ownerDocument.defaultView); | 
 |   } | 
 |  | 
 |   if (typeof x === 'number') { | 
 |     this.style.setProperty('left', (shift.x + x) + 'px'); | 
 |   } else { | 
 |     this.style.removeProperty('left'); | 
 |   } | 
 |  | 
 |   if (typeof y === 'number') { | 
 |     this.style.setProperty('top', (shift.y + y) + 'px'); | 
 |   } else { | 
 |     this.style.removeProperty('top'); | 
 |   } | 
 |  | 
 |   if (typeof x === 'number' || typeof y === 'number') { | 
 |     this.style.setProperty('position', 'absolute'); | 
 |   } else { | 
 |     this.style.removeProperty('position'); | 
 |   } | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {boolean} | 
 |  */ | 
 | Element.prototype.isScrolledToBottom = function() { | 
 |   // This code works only for 0-width border. | 
 |   // The scrollTop, clientHeight and scrollHeight are computed in double values internally. | 
 |   // However, they are exposed to javascript differently, each being either rounded (via | 
 |   // round, ceil or floor functions) or left intouch. | 
 |   // This adds up a total error up to 2. | 
 |   return Math.abs(this.scrollTop + this.clientHeight - this.scrollHeight) <= 2; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Array.<string>} nameArray | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.enclosingNodeOrSelfWithNodeNameInArray = function(nameArray) { | 
 |   for (let node = this; node && node !== this.ownerDocument; node = node.parentNodeOrShadowHost()) { | 
 |     for (let i = 0; i < nameArray.length; ++i) { | 
 |       if (node.nodeName.toLowerCase() === nameArray[i].toLowerCase()) { | 
 |         return node; | 
 |       } | 
 |     } | 
 |   } | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} nodeName | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.enclosingNodeOrSelfWithNodeName = function(nodeName) { | 
 |   return this.enclosingNodeOrSelfWithNodeNameInArray([nodeName]); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} className | 
 |  * @param {!Element=} stayWithin | 
 |  * @return {?Element} | 
 |  */ | 
 | Node.prototype.enclosingNodeOrSelfWithClass = function(className, stayWithin) { | 
 |   return this.enclosingNodeOrSelfWithClassList([className], stayWithin); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Array.<string>} classNames | 
 |  * @param {!Element=} stayWithin | 
 |  * @return {?Element} | 
 |  */ | 
 | Node.prototype.enclosingNodeOrSelfWithClassList = function(classNames, stayWithin) { | 
 |   for (let node = this; node && node !== stayWithin && node !== this.ownerDocument; | 
 |        node = node.parentNodeOrShadowHost()) { | 
 |     if (node.nodeType === Node.ELEMENT_NODE) { | 
 |       let containsAll = true; | 
 |       for (let i = 0; i < classNames.length && containsAll; ++i) { | 
 |         if (!node.classList.contains(classNames[i])) { | 
 |           containsAll = false; | 
 |         } | 
 |       } | 
 |       if (containsAll) { | 
 |         return /** @type {!Element} */ (node); | 
 |       } | 
 |     } | 
 |   } | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.enclosingShadowRoot = function() { | 
 |   let parentNode = this.parentNodeOrShadowHost(); | 
 |   while (parentNode) { | 
 |     if (parentNode instanceof ShadowRoot) { | 
 |       return parentNode; | 
 |     } | 
 |     parentNode = parentNode.parentNodeOrShadowHost(); | 
 |   } | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Node} node | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.hasSameShadowRoot = function(node) { | 
 |   return this.enclosingShadowRoot() === node.enclosingShadowRoot(); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Element} | 
 |  */ | 
 | Node.prototype.parentElementOrShadowHost = function() { | 
 |   if (this.nodeType === Node.DOCUMENT_FRAGMENT_NODE && this.host) { | 
 |     return /** @type {!Element} */ (this.host); | 
 |   } | 
 |   const node = this.parentNode; | 
 |   if (!node) { | 
 |     return null; | 
 |   } | 
 |   if (node.nodeType === Node.ELEMENT_NODE) { | 
 |     return /** @type {!Element} */ (node); | 
 |   } | 
 |   if (node.nodeType === Node.DOCUMENT_FRAGMENT_NODE) { | 
 |     return /** @type {!Element} */ (node.host); | 
 |   } | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.parentNodeOrShadowHost = function() { | 
 |   if (this.parentNode) { | 
 |     return this.parentNode; | 
 |   } | 
 |   if (this.nodeType === Node.DOCUMENT_FRAGMENT_NODE && this.host) { | 
 |     return this.host; | 
 |   } | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Selection} | 
 |  */ | 
 | Node.prototype.getComponentSelection = function() { | 
 |   let parent = this.parentNode; | 
 |   while (parent && parent.nodeType !== Node.DOCUMENT_FRAGMENT_NODE) { | 
 |     parent = parent.parentNode; | 
 |   } | 
 |   return parent instanceof ShadowRoot ? parent.getSelection() : this.window().getSelection(); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.hasSelection = function() { | 
 |   // TODO(luoe): use contains(node, {includeShadow: true}) when it is fixed for shadow dom. | 
 |   if (this instanceof Element) { | 
 |     const slots = this.querySelectorAll('slot'); | 
 |     for (const slot of slots) { | 
 |       if (Array.prototype.some.call(slot.assignedNodes(), node => node.hasSelection())) { | 
 |         return true; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   const selection = this.getComponentSelection(); | 
 |   if (selection.type !== 'Range') { | 
 |     return false; | 
 |   } | 
 |   return selection.containsNode(this, true) || selection.anchorNode.isSelfOrDescendant(this) || | 
 |       selection.focusNode.isSelfOrDescendant(this); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {!Window} | 
 |  */ | 
 | Node.prototype.window = function() { | 
 |   return /** @type {!Window} */ (this.ownerDocument.defaultView); | 
 | }; | 
 |  | 
 | Element.prototype.removeChildren = function() { | 
 |   if (this.firstChild) { | 
 |     this.textContent = ''; | 
 |   } | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} tagName | 
 |  * @param {string=} customElementType | 
 |  * @return {!Element} | 
 |  * @suppress {checkTypes} | 
 |  * @suppressGlobalPropertiesCheck | 
 |  */ | 
 | self.createElement = function(tagName, customElementType) { | 
 |   return document.createElement(tagName, {is: customElementType}); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {number|string} data | 
 |  * @return {!Text} | 
 |  * @suppressGlobalPropertiesCheck | 
 |  */ | 
 | self.createTextNode = function(data) { | 
 |   return document.createTextNode(data); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} elementName | 
 |  * @param {string=} className | 
 |  * @param {string=} customElementType | 
 |  * @suppress {checkTypes} | 
 |  * @return {!Element} | 
 |  */ | 
 | Document.prototype.createElementWithClass = function(elementName, className, customElementType) { | 
 |   const element = this.createElement(elementName, {is: customElementType}); | 
 |   if (className) { | 
 |     element.className = className; | 
 |   } | 
 |   return element; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} elementName | 
 |  * @param {string=} className | 
 |  * @param {string=} customElementType | 
 |  * @return {!Element} | 
 |  * @suppressGlobalPropertiesCheck | 
 |  */ | 
 | self.createElementWithClass = function(elementName, className, customElementType) { | 
 |   return document.createElementWithClass(elementName, className, customElementType); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} childType | 
 |  * @param {string=} className | 
 |  * @return {!Element} | 
 |  */ | 
 | Document.prototype.createSVGElement = function(childType, className) { | 
 |   const element = this.createElementNS('http://www.w3.org/2000/svg', childType); | 
 |   if (className) { | 
 |     element.setAttribute('class', className); | 
 |   } | 
 |   return element; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} childType | 
 |  * @param {string=} className | 
 |  * @return {!Element} | 
 |  * @suppressGlobalPropertiesCheck | 
 |  */ | 
 | self.createSVGElement = function(childType, className) { | 
 |   return document.createSVGElement(childType, className); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {!DocumentFragment} | 
 |  * @suppressGlobalPropertiesCheck | 
 |  */ | 
 | self.createDocumentFragment = function() { | 
 |   return document.createDocumentFragment(); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} elementName | 
 |  * @param {string=} className | 
 |  * @param {string=} customElementType | 
 |  * @return {!Element} | 
 |  */ | 
 | Element.prototype.createChild = function(elementName, className, customElementType) { | 
 |   const element = this.ownerDocument.createElementWithClass(elementName, className, customElementType); | 
 |   this.appendChild(element); | 
 |   return element; | 
 | }; | 
 |  | 
 | DocumentFragment.prototype.createChild = Element.prototype.createChild; | 
 |  | 
 | /** | 
 |  * @param {string} text | 
 |  * @return {!Text} | 
 |  */ | 
 | Element.prototype.createTextChild = function(text) { | 
 |   const element = this.ownerDocument.createTextNode(text); | 
 |   this.appendChild(element); | 
 |   return element; | 
 | }; | 
 |  | 
 | DocumentFragment.prototype.createTextChild = Element.prototype.createTextChild; | 
 |  | 
 | /** | 
 |  * @param {...string} var_args | 
 |  */ | 
 | Element.prototype.createTextChildren = function(var_args) { | 
 |   for (let i = 0, n = arguments.length; i < n; ++i) { | 
 |     this.createTextChild(arguments[i]); | 
 |   } | 
 | }; | 
 |  | 
 | DocumentFragment.prototype.createTextChildren = Element.prototype.createTextChildren; | 
 |  | 
 | /** | 
 |  * @return {number} | 
 |  */ | 
 | Element.prototype.totalOffsetLeft = function() { | 
 |   return this.totalOffset().left; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {number} | 
 |  */ | 
 | Element.prototype.totalOffsetTop = function() { | 
 |   return this.totalOffset().top; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {!{left: number, top: number}} | 
 |  */ | 
 | Element.prototype.totalOffset = function() { | 
 |   const rect = this.getBoundingClientRect(); | 
 |   return {left: rect.left, top: rect.top}; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {string} childType | 
 |  * @param {string=} className | 
 |  * @return {!Element} | 
 |  */ | 
 | Element.prototype.createSVGChild = function(childType, className) { | 
 |   const child = this.ownerDocument.createSVGElement(childType, className); | 
 |   this.appendChild(child); | 
 |   return child; | 
 | }; | 
 |  | 
 | /** | 
 |  * @unrestricted | 
 |  */ | 
 | var AnchorBox = class {  // eslint-disable-line | 
 |   /** | 
 |    * @param {number=} x | 
 |    * @param {number=} y | 
 |    * @param {number=} width | 
 |    * @param {number=} height | 
 |    */ | 
 |   constructor(x, y, width, height) { | 
 |     this.x = x || 0; | 
 |     this.y = y || 0; | 
 |     this.width = width || 0; | 
 |     this.height = height || 0; | 
 |   } | 
 |  | 
 |   /** | 
 |    * @param {number} x | 
 |    * @param {number} y | 
 |    * @return {boolean} | 
 |    */ | 
 |   contains(x, y) { | 
 |     return x >= this.x && x <= this.x + this.width && y >= this.y && y <= this.y + this.height; | 
 |   } | 
 |  | 
 |   /** | 
 |    * @param {!AnchorBox} box | 
 |    * @return {!AnchorBox} | 
 |    */ | 
 |   relativeTo(box) { | 
 |     return new AnchorBox(this.x - box.x, this.y - box.y, this.width, this.height); | 
 |   } | 
 |  | 
 |   /** | 
 |    * @param {!Element} element | 
 |    * @return {!AnchorBox} | 
 |    */ | 
 |   relativeToElement(element) { | 
 |     return this.relativeTo(element.boxInWindow(element.ownerDocument.defaultView)); | 
 |   } | 
 |  | 
 |   /** | 
 |    * @param {?AnchorBox} anchorBox | 
 |    * @return {boolean} | 
 |    */ | 
 |   equals(anchorBox) { | 
 |     return !!anchorBox && this.x === anchorBox.x && this.y === anchorBox.y && this.width === anchorBox.width && | 
 |         this.height === anchorBox.height; | 
 |   } | 
 | }; | 
 |  | 
 | /** @constructor */ | 
 | self.AnchorBox = AnchorBox; | 
 |  | 
 | /** | 
 |  * @param {?Window=} targetWindow | 
 |  * @return {!AnchorBox} | 
 |  */ | 
 | Element.prototype.boxInWindow = function(targetWindow) { | 
 |   targetWindow = targetWindow || this.ownerDocument.defaultView; | 
 |  | 
 |   const anchorBox = new AnchorBox(); | 
 |   let curElement = this; | 
 |   let curWindow = this.ownerDocument.defaultView; | 
 |   while (curWindow && curElement) { | 
 |     anchorBox.x += curElement.totalOffsetLeft(); | 
 |     anchorBox.y += curElement.totalOffsetTop(); | 
 |     if (curWindow === targetWindow) { | 
 |       break; | 
 |     } | 
 |     curElement = curWindow.frameElement; | 
 |     curWindow = curWindow.parent; | 
 |   } | 
 |  | 
 |   anchorBox.width = Math.min(this.offsetWidth, targetWindow.innerWidth - anchorBox.x); | 
 |   anchorBox.height = Math.min(this.offsetHeight, targetWindow.innerHeight - anchorBox.y); | 
 |   return anchorBox; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {boolean=} preventDefault | 
 |  */ | 
 | Event.prototype.consume = function(preventDefault) { | 
 |   this.stopImmediatePropagation(); | 
 |   if (preventDefault) { | 
 |     this.preventDefault(); | 
 |   } | 
 |   this.handled = true; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {number=} start | 
 |  * @param {number=} end | 
 |  * @return {!Text} | 
 |  */ | 
 | Text.prototype.select = function(start, end) { | 
 |   start = start || 0; | 
 |   end = end || this.textContent.length; | 
 |  | 
 |   if (start < 0) { | 
 |     start = end + start; | 
 |   } | 
 |  | 
 |   const selection = this.getComponentSelection(); | 
 |   selection.removeAllRanges(); | 
 |   const range = this.ownerDocument.createRange(); | 
 |   range.setStart(this, start); | 
 |   range.setEnd(this, end); | 
 |   selection.addRange(range); | 
 |   return this; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?number} | 
 |  */ | 
 | Element.prototype.selectionLeftOffset = function() { | 
 |   // Calculate selection offset relative to the current element. | 
 |  | 
 |   const selection = this.getComponentSelection(); | 
 |   if (!selection.containsNode(this, true)) { | 
 |     return null; | 
 |   } | 
 |  | 
 |   let leftOffset = selection.anchorOffset; | 
 |   let node = selection.anchorNode; | 
 |  | 
 |   while (node !== this) { | 
 |     while (node.previousSibling) { | 
 |       node = node.previousSibling; | 
 |       leftOffset += node.textContent.length; | 
 |     } | 
 |     node = node.parentNodeOrShadowHost(); | 
 |   } | 
 |  | 
 |   return leftOffset; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {...!Node} var_args | 
 |  */ | 
 | Node.prototype.appendChildren = function(var_args) { | 
 |   for (let i = 0, n = arguments.length; i < n; ++i) { | 
 |     this.appendChild(arguments[i]); | 
 |   } | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {string} | 
 |  */ | 
 | Node.prototype.deepTextContent = function() { | 
 |   return this.childTextNodes() | 
 |       .map(function(node) { | 
 |         return node.textContent; | 
 |       }) | 
 |       .join(''); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {!Array.<!Node>} | 
 |  */ | 
 | Node.prototype.childTextNodes = function() { | 
 |   let node = this.traverseNextTextNode(this); | 
 |   const result = []; | 
 |   const nonTextTags = {'STYLE': 1, 'SCRIPT': 1}; | 
 |   while (node) { | 
 |     if (!nonTextTags[node.parentElement.nodeName]) { | 
 |       result.push(node); | 
 |     } | 
 |     node = node.traverseNextTextNode(this); | 
 |   } | 
 |   return result; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {?Node} node | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.isAncestor = function(node) { | 
 |   if (!node) { | 
 |     return false; | 
 |   } | 
 |  | 
 |   let currentNode = node.parentNodeOrShadowHost(); | 
 |   while (currentNode) { | 
 |     if (this === currentNode) { | 
 |       return true; | 
 |     } | 
 |     currentNode = currentNode.parentNodeOrShadowHost(); | 
 |   } | 
 |   return false; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {?Node} descendant | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.isDescendant = function(descendant) { | 
 |   return !!descendant && descendant.isAncestor(this); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {?Node} node | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.isSelfOrAncestor = function(node) { | 
 |   return !!node && (node === this || this.isAncestor(node)); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {?Node} node | 
 |  * @return {boolean} | 
 |  */ | 
 | Node.prototype.isSelfOrDescendant = function(node) { | 
 |   return !!node && (node === this || this.isDescendant(node)); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Node=} stayWithin | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.traverseNextNode = function(stayWithin) { | 
 |   if (this.shadowRoot) { | 
 |     return this.shadowRoot; | 
 |   } | 
 |  | 
 |   const distributedNodes = this instanceof HTMLSlotElement ? this.assignedNodes() : []; | 
 |  | 
 |   if (distributedNodes.length) { | 
 |     return distributedNodes[0]; | 
 |   } | 
 |  | 
 |   if (this.firstChild) { | 
 |     return this.firstChild; | 
 |   } | 
 |  | 
 |   let node = this; | 
 |   while (node) { | 
 |     if (stayWithin && node === stayWithin) { | 
 |       return null; | 
 |     } | 
 |  | 
 |     const sibling = nextSibling(node); | 
 |     if (sibling) { | 
 |       return sibling; | 
 |     } | 
 |  | 
 |     node = node.assignedSlot || node.parentNodeOrShadowHost(); | 
 |   } | 
 |  | 
 |   /** | 
 |    * @param {!Node} node | 
 |    * @return {?Node} | 
 |    */ | 
 |   function nextSibling(node) { | 
 |     if (!node.assignedSlot) { | 
 |       return node.nextSibling; | 
 |     } | 
 |     const distributedNodes = node.assignedSlot.assignedNodes(); | 
 |  | 
 |     const position = Array.prototype.indexOf.call(distributedNodes, node); | 
 |     if (position + 1 < distributedNodes.length) { | 
 |       return distributedNodes[position + 1]; | 
 |     } | 
 |     return null; | 
 |   } | 
 |  | 
 |   return null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Node=} stayWithin | 
 |  * @return {?Node} | 
 |  */ | 
 | Node.prototype.traversePreviousNode = function(stayWithin) { | 
 |   if (stayWithin && this === stayWithin) { | 
 |     return null; | 
 |   } | 
 |   let node = this.previousSibling; | 
 |   while (node && node.lastChild) { | 
 |     node = node.lastChild; | 
 |   } | 
 |   if (node) { | 
 |     return node; | 
 |   } | 
 |   return this.parentNodeOrShadowHost(); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {*} text | 
 |  * @param {string=} placeholder | 
 |  * @return {boolean} true if was truncated | 
 |  */ | 
 | Node.prototype.setTextContentTruncatedIfNeeded = function(text, placeholder) { | 
 |   // Huge texts in the UI reduce rendering performance drastically. | 
 |   // Moreover, Blink/WebKit uses <unsigned short> internally for storing text content | 
 |   // length, so texts longer than 65535 are inherently displayed incorrectly. | 
 |   const maxTextContentLength = 10000; | 
 |  | 
 |   if (typeof text === 'string' && text.length > maxTextContentLength) { | 
 |     this.textContent = typeof placeholder === 'string' ? placeholder : text.trimMiddle(maxTextContentLength); | 
 |     return true; | 
 |   } | 
 |  | 
 |   this.textContent = text; | 
 |   return false; | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Node} | 
 |  */ | 
 | Event.prototype.deepElementFromPoint = function() { | 
 |   // Some synthetic events have zero coordinates which lead to a wrong element. Better return nothing in this case. | 
 |   if (!this.which && !this.pageX && !this.pageY && !this.clientX && !this.clientY && !this.movementX && | 
 |       !this.movementY) { | 
 |     return null; | 
 |   } | 
 |   const root = this.target && this.target.getComponentRoot(); | 
 |   return root ? root.deepElementFromPoint(this.pageX, this.pageY) : null; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {number} x | 
 |  * @param {number} y | 
 |  * @return {?Node} | 
 |  */ | 
 | Document.prototype.deepElementFromPoint = function(x, y) { | 
 |   let container = this; | 
 |   let node = null; | 
 |   while (container) { | 
 |     const innerNode = container.elementFromPoint(x, y); | 
 |     if (!innerNode || node === innerNode) { | 
 |       break; | 
 |     } | 
 |     node = innerNode; | 
 |     container = node.shadowRoot; | 
 |   } | 
 |   return node; | 
 | }; | 
 |  | 
 | DocumentFragment.prototype.deepElementFromPoint = Document.prototype.deepElementFromPoint; | 
 |  | 
 | /** | 
 |  * @return {?Element} | 
 |  */ | 
 | Document.prototype.deepActiveElement = function() { | 
 |   let activeElement = this.activeElement; | 
 |   while (activeElement && activeElement.shadowRoot && activeElement.shadowRoot.activeElement) { | 
 |     activeElement = activeElement.shadowRoot.activeElement; | 
 |   } | 
 |   return activeElement; | 
 | }; | 
 |  | 
 | DocumentFragment.prototype.deepActiveElement = Document.prototype.deepActiveElement; | 
 |  | 
 | /** | 
 |  * @return {boolean} | 
 |  */ | 
 | Element.prototype.hasFocus = function() { | 
 |   const root = this.getComponentRoot(); | 
 |   return !!root && this.isSelfOrAncestor(root.activeElement); | 
 | }; | 
 |  | 
 | /** | 
 |  * @return {?Document|?DocumentFragment} | 
 |  */ | 
 | Node.prototype.getComponentRoot = function() { | 
 |   let node = this; | 
 |   while (node && node.nodeType !== Node.DOCUMENT_FRAGMENT_NODE && node.nodeType !== Node.DOCUMENT_NODE) { | 
 |     node = node.parentNode; | 
 |   } | 
 |   return /** @type {?Document|?DocumentFragment} */ (node); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Element} element | 
 |  * @param {function(!Event)} callback | 
 |  */ | 
 | self.onInvokeElement = function(element, callback) { | 
 |   element.addEventListener('keydown', event => { | 
 |     if (self.isEnterOrSpaceKey(event)) { | 
 |       callback(event); | 
 |     } | 
 |   }); | 
 |   element.addEventListener('click', event => callback(event)); | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Event} event | 
 |  * @return {boolean} | 
 |  */ | 
 | self.isEnterKey = function(event) { | 
 |   // Check if in IME. | 
 |   return event.keyCode !== 229 && event.key === 'Enter'; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Event} event | 
 |  * @return {boolean} | 
 |  */ | 
 | self.isEnterOrSpaceKey = function(event) { | 
 |   return self.isEnterKey(event) || event.key === ' '; | 
 | }; | 
 |  | 
 | /** | 
 |  * @param {!Event} event | 
 |  * @return {boolean} | 
 |  */ | 
 | self.isEscKey = function(event) { | 
 |   return event.keyCode === 27; | 
 | }; | 
 |  | 
 | // DevTools front-end still assumes that | 
 | //   classList.toggle('a', undefined) works as | 
 | //   classList.toggle('a', false) rather than as | 
 | //   classList.toggle('a'); | 
 | (function() { | 
 | const originalToggle = DOMTokenList.prototype.toggle; | 
 | DOMTokenList.prototype['toggle'] = function(token, force) { | 
 |   if (arguments.length === 1) { | 
 |     force = !this.contains(token); | 
 |   } | 
 |   return originalToggle.call(this, token, !!force); | 
 | }; | 
 | })(); |