DevTools: make ElementsTreeOutline shadow dom-based.

Source/devtools/front_end/ui/DOMExtension.js

 /*
  * 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.
@@ skipping 638 matching lines @@
             node = node.previousSibling;
             leftOffset += node.textContent.length;
         }
         node = node.parentNodeOrShadowHost();
     }
 
     return leftOffset;
 }
 
 /**
+ * @return {string}
+ */
+Node.prototype.deepTextContent = function()
+{
+    var node = this.traverseNextTextNode(this);
+    var result = [];
+    var nonTextTags = { "STYLE": 1, "SCRIPT": 1 };
+    while (node) {
+        if (!nonTextTags[node.parentElement.nodeName])
+            result.push(node.textContent);
+        node = node.traverseNextTextNode(this);
+    }
+    return result.join("");
+}
+
+/**
  * @param {?Node} node
  * @return {boolean}
  */
 Node.prototype.isAncestor = function(node)
 {
     if (!node)
         return false;
 
     var currentNode = node.parentNodeOrShadowHost();
     while (currentNode) {
@@ skipping 30 matching lines @@
 {
     return !!node && (node === this || this.isDescendant(node));
 }
 
 /**
  * @param {!Node=} stayWithin
  * @return {?Node}
  */
 Node.prototype.traverseNextNode = function(stayWithin)
 {
-    var node = this.firstChild;
-    if (node)
-        return node;
+    if (this.firstChild)
+        return this.firstChild;
+
+    if (this.shadowRoot)
+        return this.shadowRoot;
 
     if (stayWithin && this === stayWithin)
         return null;
 
-    node = this.nextSibling;
+    var node = this.nextSibling;
     if (node)
         return node;
 
     node = this;
     while (node && !node.nextSibling && (!stayWithin || !node.parentNodeOrShadowHost() || node.parentNodeOrShadowHost() !== stayWithin))
         node = node.parentNodeOrShadowHost();
     if (!node)
         return null;
 
     return node.nextSibling;
@@ skipping 65 matching lines @@
  */
 function isEnterKey(event) {
     // Check if in IME.
     return event.keyCode !== 229 && event.keyIdentifier === "Enter";
 }
 
 function consumeEvent(e)
 {
     e.consume();
 }