DevTools: Show top level event initiator when a child is selected.

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

Index: third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js
diff --git a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js
index 296742004b644557735756968026e8b5259ca228..2566939b2eee50faffe7b976215ce25fff5fcc78 100644
--- a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js
+++ b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineFlameChartDataProvider.js
@@ -865,20 +865,24 @@ Timeline.TimelineFlameChartDataProvider = class {
       return false;
     this._lastInitiatorEntry = entryIndex;
     var event = this.eventByIndex(entryIndex);
-    var initiator = event && TimelineModel.TimelineData.forEvent(event).initiator();
-    if (initiator && !this._isVisible(initiator))
-      initiator = null;
     var td = this._timelineData;
-    if (td.flowStartTimes.length || initiator) {
-      td.flowStartTimes = [];
-      td.flowStartLevels = [];
-      td.flowEndTimes = [];
-      td.flowEndLevels = [];
+    td.flowStartTimes = [];
+    td.flowStartLevels = [];
+    td.flowEndTimes = [];
+    td.flowEndLevels = [];
+    // Find the closest ancestor with an initiator.
+    var initiator;
+    for (; event; event = TimelineModel.TimelineModel.parentEvent(event)) {
+      if (!this._isVisible(event))
+        continue;
+      initiator = TimelineModel.TimelineData.forEvent(event).initiator();
+      if (initiator)
+        break;
     }
-    if (!initiator)
+    if (!event || !initiator || !this._isVisible(initiator))

[caseq, 2017/03/29 22:08:20]

nit: first clause is redundant

[alph, 2017/03/29 22:16:57]

Done.

       return true;
-    var initiatorIndex = initiator[Timeline.TimelineFlameChartDataProvider._indexSymbol];
     var eventIndex = event[Timeline.TimelineFlameChartDataProvider._indexSymbol];
+    var initiatorIndex = initiator[Timeline.TimelineFlameChartDataProvider._indexSymbol];
     td.flowStartTimes.push(initiator.endTime || initiator.startTime);
     td.flowStartLevels.push(td.entryLevels[initiatorIndex]);
     td.flowEndTimes.push(event.startTime);