DevTools: Switch to using fast stack iterator to collect stacks during timeline recording.

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
  * @param {!ProfilerAgent.CPUProfile} profile
  */
 WebInspector.CPUProfileDataModel = function(profile)
 {
     this.profileHead = profile.head;
     this.samples = profile.samples;
     this.timestamps = profile.timestamps;
     this.profileStartTime = profile.startTime * 1000;
     this.profileEndTime = profile.endTime * 1000;
     this._assignParentsInProfile();
     if (this.samples) {
+        this._sortSamples();
         this._normalizeTimestamps();
         this._buildIdToNodeMap();
         this._fixMissingSamples();
     }
     if (!WebInspector.moduleSetting("showNativeFunctionsInJSProfile").get())
         this._filterNativeFrames();
     this._assignDepthsInProfile();
     this._calculateTimes(profile);
 }
 
@@ skipping 120 matching lines @@
             var length = children.length;
             for (var i = 0; i < length; ++i) {
                 var child = children[i];
                 child.depth = depth;
                 if (child.children.length)
                     nodesToTraverse.push(child);
             }
         }
     },
 
+    _sortSamples: function()
+    {
+        var timestamps = this.timestamps;
+        if (!timestamps)
+            return;
+        var samples = this.samples;
+        var indices = timestamps.map((x, index) => index);
+        indices.sort((a, b) => timestamps[a] - timestamps[b]);
+        for (var i = 0; i < timestamps.length; ++i) {
+            var index = indices[i];
+            if (index === i)
+                continue;
+            // Move items in a cycle.
+            var savedTimestamp = timestamps[i];
+            var savedSample = samples[i];
+            var currentIndex = i;
+            while (index !== i) {
+                samples[currentIndex] = samples[index];
+                timestamps[currentIndex] = timestamps[index];
+                currentIndex = index;
+                index = indices[index];
+                indices[currentIndex] = currentIndex;
+            }
+            samples[currentIndex] = savedSample;
+            timestamps[currentIndex] = savedTimestamp;
+        }
+    },
+
     _normalizeTimestamps: function()
     {
         var timestamps = this.timestamps;
         if (!timestamps) {
             // Support loading old CPU profiles that are missing timestamps.
             // Derive timestamps from profile start and stop times.
             var profileStartTime = this.profileStartTime;
             var interval = (this.profileEndTime - profileStartTime) / this.samples.length;
             timestamps = new Float64Array(this.samples.length + 1);
             for (var i = 0; i < timestamps.length; ++i)
@@ skipping 199 matching lines @@
     /**
      * @param {number} index
      * @return {!ProfilerAgent.CPUProfileNode}
      */
     nodeByIndex: function(index)
     {
         return this._idToNode[this.samples[index]];
     }
 
 }