DevTools: Show screenshots on the main flamechart

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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.
@@ skipping 1802 matching lines @@
   /**
    * @param {!TimelineModel.TimelineModel.PageFrame} frame
    * @param {number=} trimAt
    */
   static displayNameForFrame(frame, trimAt) {
     var url = frame.url;
     if (!trimAt)
       trimAt = 30;
     return url.startsWith('about:') ? `"${frame.name.trimMiddle(trimAt)}"` : frame.url.trimEnd(trimAt);
   }
+
+  /**
+   * @param {!SDK.FilmStripModel} filmStripModel
+   * @param {!TimelineModel.TimelineFrame} frame
+   * @return {?SDK.FilmStripModel.Frame}
+   */
+  static filmStripModelFrame(filmStripModel, frame) {

[caseq, 2017/05/01 22:13:35]

Let's rather move it to PerformanceModel, it does not look particularly specific
to UI.

[alph, 2017/05/02 18:31:13]

Done.

+    var screenshotTime = frame.idle ?
+        frame.startTime :
+        frame.endTime;  // For idle frames, look at the state at the beginning of the frame.
+    var filmStripFrame = filmStripModel.frameByTimestamp(screenshotTime);
+    if (filmStripFrame && filmStripFrame.timestamp - frame.endTime > 10)
+      filmStripFrame = null;

[caseq, 2017/05/01 22:13:35]

nit: return null instead.

[alph, 2017/05/02 18:31:13]

Done.

+    return filmStripFrame;
+  }
 };
 
 /**
  * @unrestricted
  */
 Timeline.TimelineRecordStyle = class {
   /**
    * @param {string} title
    * @param {!Timeline.TimelineCategory} category
    * @param {boolean=} hidden
@@ skipping 463 matching lines @@
    * @param {string=} warningType
    */
   appendWarningRow(event, warningType) {
     var warning = Timeline.TimelineUIUtils.eventWarning(event, warningType);
     if (warning)
       this.appendElementRow(Common.UIString('Warning'), warning, true);
   }
 };
 
 Timeline.TimelineUIUtils._categoryBreakdownCacheSymbol = Symbol('categoryBreakdownCache');