DevTools: Show event initiator on Flame Chart for selected entries

third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 691 matching lines @@
    * @param {!SDK.TracingModel.Event} event
    * @param {number} level
    */
   _appendEvent(event, level) {
     var index = this._entryData.length;
     this._entryData.push(event);
     this._timelineData.entryLevels[index] = level;
     this._timelineData.entryTotalTimes[index] =
         event.duration || Timeline.TimelineFlameChartDataProvider.InstantEventVisibleDurationMs;
     this._timelineData.entryStartTimes[index] = event.startTime;
+    event[Timeline.TimelineFlameChartDataProvider._indexSymbol] = index;
   }
 
   /**
    * @param {!SDK.TracingModel.AsyncEvent} asyncEvent
    * @param {number} level
    */
   _appendAsyncEvent(asyncEvent, level) {
     if (SDK.TracingModel.isNestableAsyncPhase(asyncEvent.phase)) {
       // FIXME: also add steps once we support event nesting in the FlameChart.
       this._appendEvent(asyncEvent, level);
@@ skipping 144 matching lines @@
 
   /**
    * @param {!SDK.TracingModel.Event} event
    * @return {boolean}
    */
   _isVisible(event) {
     return this._filters.every(function(filter) {
       return filter.accept(event);
     });
   }
+
+  /**
+   * @param {number} entryIndex
+   * @return {boolean}
+   */
+  buildFlowForInitiator(entryIndex) {
+    if (this._lastInitiatorEntry === entryIndex)
+      return false;
+    this._lastInitiatorEntry = entryIndex;
+    var event = this._entryType(entryIndex) === Timeline.TimelineFlameChartEntryType.Event ?
+        /** @type {!SDK.TracingModel.Event} */ (this._entryData[entryIndex]) :
+        null;
+    var td = this._timelineData;
+    var initiator = event && TimelineModel.TimelineData.forEvent(event).initiator();
+    if (initiator && !this._isVisible(initiator))
+      initiator = null;
+    if (td.flowStartTimes.length || initiator) {
+      td.flowStartTimes = [];
+      td.flowStartLevels = [];
+      td.flowEndTimes = [];
+      td.flowEndLevels = [];
+    }
+    if (!initiator)
+      return true;
+    var initiatorIndex = initiator[Timeline.TimelineFlameChartDataProvider._indexSymbol];
+    var eventIndex = event[Timeline.TimelineFlameChartDataProvider._indexSymbol];
+    td.flowStartTimes.push(initiator.endTime || initiator.startTime);
+    td.flowStartLevels.push(td.entryLevels[initiatorIndex]);
+    td.flowEndTimes.push(event.startTime);
+    td.flowEndLevels.push(td.entryLevels[eventIndex]);
+    return true;
+  }
 };
 
 Timeline.TimelineFlameChartDataProvider.InstantEventVisibleDurationMs = 0.001;
+Timeline.TimelineFlameChartDataProvider._indexSymbol = Symbol('index');