[DevTools] JSONView parsing smarter

third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js

Index: third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js
diff --git a/third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js b/third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js
index dfa926c0ba32ebabaa210b6b4cbeee93e0c7c806..b990d423872d0695012cb5f18f13f035bd3e9716 100644
--- a/third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js
+++ b/third_party/WebKit/Source/devtools/front_end/es_tree/ESTreeWalker.js
@@ -4,19 +4,29 @@
 
 /**
  * @constructor
- * @param {function(!ESTree.Node)} beforeVisit
+ * @param {function(!ESTree.Node):(!Object|undefined)} beforeVisit
  * @param {function(!ESTree.Node)=} afterVisit
  */
 WebInspector.ESTreeWalker = function(beforeVisit, afterVisit)
 {
     this._beforeVisit = beforeVisit;
     this._afterVisit = afterVisit || new Function();
+    this._walkNulls = false;
 }
 
+/** @typedef {!Object} WebInspector.ESTreeWalker.SkipSubtree */
 WebInspector.ESTreeWalker.SkipSubtree = {};
 
 WebInspector.ESTreeWalker.prototype = {
     /**
+     * @param {boolean} value
+     */
+    setWalkNulls: function(value)
+    {
+        this._walkNulls = value;
+    },
+
+    /**
      * @param {!ESTree.Node} ast
      */
     walk: function(ast)
@@ -30,6 +40,14 @@ WebInspector.ESTreeWalker.prototype = {
      */
     _innerWalk: function(node, parent)
     {
+        if (!node && parent && this._walkNulls) {
+            node = /** @type {!ESTree.Node} */ ({
+                type: "Literal",
+                raw: "null",
+                value: null
+            });
+        }
+
         if (!node)
             return;
         node.parent = parent;