Move divider detection and creation onto TimelineUIUtils instance

Source/devtools/front_end/timeline/TracingTimelineModel.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.
 
 /**
  * @param {!WebInspector.TracingModel} tracingModel
  * @constructor
  * @extends {WebInspector.TimelineModel}
  */
 WebInspector.TracingTimelineModel = function(tracingModel)
@@ skipping 209 matching lines @@
         for (var i = 0, size = mainThreadEvents.length; i < size; ++i) {
             var event = mainThreadEvents[i];
             while (recordStack.length) {
                 var top = recordStack.peekLast();
                 if (top._event.endTime >= event.startTime)
                     break;
                 recordStack.pop();
             }
             var parentRecord = recordStack.peekLast() || null;
             var record = new WebInspector.TracingTimelineModel.TraceEventRecord(this, event, parentRecord);
-            if (WebInspector.TimelineUIUtils.isEventDivider(record))
+            if (WebInspector.TracingTimelineUIUtils.isEventDivider(record))
                 this._eventDividerRecords.push(record);
             if (!recordStack.length)
                 this._addTopLevelRecord(record);
             if (event.endTime)
                 recordStack.push(record);
         }
     },
 
     /**
      * @param {!WebInspector.TracingTimelineModel.TraceEventRecord} record
@@ skipping 434 matching lines @@
     },
 
     /**
      * @return {!WebInspector.TracingModel.Event}
      */
     traceEvent: function()
     {
         return this._event;
     }
 }