Support warning decorations in Timeline flame chart based on trace events

Source/devtools/front_end/timeline/TracingModel.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.Object}
  */
@@ skipping 156 matching lines @@
      * @param {!Array.<!WebInspector.TracingModel.EventPayload>} events
      */
     _eventsCollected: function(events)
     {
         for (var i = 0; i < events.length; ++i)
             this._addEvent(events[i]);
     },
 
     _tracingComplete: function()
     {
+        this._calculateWarnings();
+
         this._active = false;
         if (!this._pendingStopCallback)
             return;
         this._pendingStopCallback();
         this._pendingStopCallback = null;
     },
+    
+    _calculateWarnings: function()
+    {
+        var events = this._inspectedTargetMainThreadEvents;
+        var currentScriptEvent = null;
+        for (var i = 0, l = events.length; i < l; i++) {
+            var event = events[i];
+            if (currentScriptEvent && event.startTime > currentScriptEvent.endTime)
+                currentScriptEvent = null;
+            if (event.name === WebInspector.TimelineModel.RecordType.Layout && currentScriptEvent)
+                this._eventToWarning.put(event, WebInspector.UIString("Forced synchronous layout is a possible performance bottleneck."));
+            if (event.name === WebInspector.TimelineModel.RecordType.EvaluateScript || event.name === WebInspector.TimelineModel.RecordType.FunctionCall)

[caseq, 2014/05/07 15:44:33]

Looks like this belongs to a higher level than tracing model. Can we do this
elsewhere?

[yurys, 2014/05/08 07:46:46]

Done. Extracted this code into TracingModel.EventBindings which will contain
derived data for the tracing model similar to InterRecordBingings in current
timeline implementation.

+                currentScriptEvent = event;
+        }
+    },
+
+    /**
+     * @param {!WebInspector.TracingModel.Event} event
+     * @return {?string}
+     */
+    eventWarning: function(event)
+    {
+        return this._eventToWarning.get(event);
+    },
 
     reset: function()
     {
         this._processById = {};
         this._minimumRecordTime = null;
         this._maximumRecordTime = null;
         this._sessionId = null;
         this._inspectedTargetProcessId = null;
         this._inspectedTargetMainThread = null;
         this._inspectedTargetMainThreadEvents = [];
         this._inspectedTargetLayerTreeHostId = 0;
         this._frameLifecycleEvents = [];
+        this._eventToWarning = new Map();
     },
 
     /**
       * @param {!WebInspector.TracingModel.EventPayload} payload
       */
     _addEvent: function(payload)
     {
         var process = this._processById[payload.pid];
         if (!process) {
             process = new WebInspector.TracingModel.Process(payload.pid);
@@ skipping 340 matching lines @@
     dataCollected: function(data)
     {
         this._tracingModel._eventsCollected(data);
     },
 
     tracingComplete: function()
     {
         this._tracingModel._tracingComplete();
     }
 }