Move divider detection and creation onto TimelineUIUtils instance

Source/devtools/front_end/timeline/TracingTimelineUIUtils.js

Index: Source/devtools/front_end/timeline/TracingTimelineUIUtils.js
diff --git a/Source/devtools/front_end/timeline/TracingTimelineUIUtils.js b/Source/devtools/front_end/timeline/TracingTimelineUIUtils.js
index 571942273573601cbe92eee0adc1cc2f9588aebb..50cf0d35039c83db4dcd323798233cdd0df5d118 100644
--- a/Source/devtools/front_end/timeline/TracingTimelineUIUtils.js
+++ b/Source/devtools/front_end/timeline/TracingTimelineUIUtils.js
@@ -41,6 +41,15 @@ WebInspector.TracingTimelineUIUtils.prototype = {
 
     /**
      * @param {!WebInspector.TimelineModel.Record} record
+     * @return {boolean}
+     */
+    isEventDivider: function(record)
+    {
+        return WebInspector.TracingTimelineUIUtils.isEventDivider(record);
+    },
+
+    /**
+     * @param {!WebInspector.TimelineModel.Record} record
      * @return {?Object}
      */
     countersForRecord: function(record)
@@ -83,6 +92,16 @@ WebInspector.TracingTimelineUIUtils.prototype = {
         WebInspector.TracingTimelineUIUtils.buildTraceEventDetails(record.traceEvent(), tracingTimelineModel, linkifier, callback, loadedFromFile, record.target());
     },
 
+    /**
+     * @param {string} recordType
+     * @param {string=} title
+     * @return {!Element}
+     */
+    createEventDivider: function(recordType, title)
+    {
+        return WebInspector.TracingTimelineUIUtils._createEventDivider(recordType, title);
+    },
+
     __proto__: WebInspector.TimelineUIUtils.prototype
 }
 
@@ -192,6 +211,22 @@ WebInspector.TracingTimelineUIUtils.styleForTraceEvent = function(name)
 }
 
 /**
+ * @param {!WebInspector.TimelineModel.Record} record
+ * @return {boolean}
+ */
+WebInspector.TracingTimelineUIUtils.isEventDivider = function(record)
+{
+    var recordTypes = WebInspector.TracingTimelineModel.RecordType;
+    if (record.type() === recordTypes.TimeStamp)
+        return true;
+    if (record.type() === recordTypes.MarkFirstPaint)
+        return true;
+    if (record.type() === recordTypes.MarkDOMContent || record.type() === recordTypes.MarkLoad)
+        return record.data()["isMainFrame"];
+    return false;
+}
+
+/**
  * @param {!WebInspector.TracingModel.Event} event
  * @param {!WebInspector.Linkifier} linkifier
  * @param {boolean} loadedFromFile
@@ -629,3 +664,31 @@ WebInspector.TracingTimelineUIUtils._buildPicturePreviewContent = function(encod
         callback(container);
     }
 }
+
+/**
+ * @param {string} recordType
+ * @param {string=} title
+ * @return {!Element}
+ */
+WebInspector.TracingTimelineUIUtils._createEventDivider = function(recordType, title)
+{
+    var eventDivider = document.createElement("div");
+    eventDivider.className = "resources-event-divider";
+    var recordTypes = WebInspector.TracingTimelineModel.RecordType;
+
+    if (recordType === recordTypes.MarkDOMContent)
+        eventDivider.className += " resources-blue-divider";
+    else if (recordType === recordTypes.MarkLoad)
+        eventDivider.className += " resources-red-divider";
+    else if (recordType === recordTypes.MarkFirstPaint)
+        eventDivider.className += " resources-green-divider";
+    else if (recordType === recordTypes.TimeStamp)
+        eventDivider.className += " resources-orange-divider";
+    else if (recordType === recordTypes.BeginFrame)
+        eventDivider.className += " timeline-frame-divider";
+
+    if (title)
+        eventDivider.title = title;
+
+    return eventDivider;
+}