DevTools: Support loading of legacy CPU profile format.

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.CPUProfileNode} node
  * @param {number} sampleTime
  */
@@ skipping 24 matching lines @@
  * @param {!ProfilerAgent.CPUProfile} profile
  */
 WebInspector.CPUProfileDataModel = function(profile)
 {
     this.samples = profile.samples;
     this.timestamps = profile.timestamps;
     // Convert times from sec to msec.
     this.profileStartTime = profile.startTime * 1000;
     this.profileEndTime = profile.endTime * 1000;
     this.totalHitCount = 0;
+    this._compatibilityConversionHeadToNodes(profile);
     this.profileHead = this._translateProfileTree(profile.nodes);
     WebInspector.ProfileTreeModel.call(this, this.profileHead);
     this._extractMetaNodes();
     if (this.samples) {
         this._buildIdToNodeMap();
         this._sortSamples();
         this._normalizeTimestamps();
     }
 }
 
 WebInspector.CPUProfileDataModel.prototype = {
     /**
+     * @param {!ProfilerAgent.CPUProfile} profile
+     */
+    _compatibilityConversionHeadToNodes: function(profile)
+    {
+        if (!profile.head || profile.nodes)
+            return;
+        /** @type {!Array<!ProfilerAgent.CPUProfileNode>} */
+        var nodes = [];
+        convertNodesTree(profile.head);
+        profile.nodes = nodes;
+        profile.head = null;

[dgozman, 2016/08/18 01:55:15]

Maybe delete profile.head?

[alph, 2016/08/18 05:22:48]

Assigning null seems to be better from v8 performance perspective, as it does
not create a new v8 class.

[dgozman, 2016/08/18 05:30:31]

Sure, but assigning null makes profile not conform to protocol definition.

+        /**
+         * @param {!ProfilerAgent.CPUProfileNode} node
+         * @return {number}
+         */
+        function convertNodesTree(node)
+        {
+            nodes.push(node);
+            node.children = (/** @type {!Array<!ProfilerAgent.CPUProfileNode>} */(node.children)).map(convertNodesTree);
+            return node.id;
+        }
+    },
+
+    /**
      * @param {!Array<!ProfilerAgent.CPUProfileNode>} nodes
      * @return {!WebInspector.CPUProfileNode}
      */
     _translateProfileTree: function(nodes)
     {
         /**
          * @param {!ProfilerAgent.CPUProfileNode} node
          * @return {boolean}
          */
         function isNativeNode(node)
@@ skipping 230 matching lines @@
      * @param {number} index
      * @return {?WebInspector.CPUProfileNode}
      */
     nodeByIndex: function(index)
     {
         return this._idToNode.get(this.samples[index]) || null;
     },
 
     __proto__: WebInspector.ProfileTreeModel.prototype
 }