DevTools: Support profile trees encoded with parents rather than children.

third_party/WebKit/Source/devtools/front_end/sdk/CPUProfileDataModel.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @extends {WebInspector.ProfileNode}
  * @param {!ProfilerAgent.ProfileNode} node
  * @param {number} sampleTime
  */
@@ skipping 102 matching lines @@
         /**
          * @param {!ProfilerAgent.ProfileNode} node
          * @return {boolean}
          */
         function isNativeNode(node)
         {
             if (node.callFrame)
                 return !!node.callFrame.url && node.callFrame.url.startsWith("native ");
             return !!node.url && node.url.startsWith("native ");
         }
+        /**
+         * @param {!Array<!ProfilerAgent.ProfileNode>} nodes
+         */
+        function buildChildrenFromParents(nodes)
+        {
+            if (nodes[0].children)
+                return;
+            nodes[0].children = [];
+            for (var i = 1; i < nodes.length; ++i) {
+                var node = nodes[i];
+                var parentNode = nodeByIdMap.get(node.parent);
+                if (parentNode.children)
+                    parentNode.children.push(node.id);
+                else
+                    parentNode.children = [node.id];
+            }
+        }
         /** @type {!Map<number, !ProfilerAgent.ProfileNode>} */
         var nodeByIdMap = new Map();
         for (var i = 0; i < nodes.length; ++i) {
             var node = nodes[i];
             nodeByIdMap.set(node.id, node);
         }
+        buildChildrenFromParents(nodes);
         this.totalHitCount = nodes.reduce((acc, node) => acc + node.hitCount, 0);
         var sampleTime = (this.profileEndTime - this.profileStartTime) / this.totalHitCount;
         var keepNatives = !!WebInspector.moduleSetting("showNativeFunctionsInJSProfile").get();
         var root = nodes[0];
         /** @type {!Map<number, number>} */
         var idMap = new Map([[root.id, root.id]]);
         var resultRoot = new WebInspector.CPUProfileNode(root, sampleTime);
         var parentNodeStack = root.children.map(() => resultRoot);
         var sourceNodeStack = root.children.map(id => nodeByIdMap.get(id));
         while (sourceNodeStack.length) {
@@ skipping 211 matching lines @@
      * @param {number} index
      * @return {?WebInspector.CPUProfileNode}
      */
     nodeByIndex: function(index)
     {
         return this._idToNode.get(this.samples[index]) || null;
     },
 
     __proto__: WebInspector.ProfileTreeModel.prototype
 }