DevTools: [timeline] Include other thread costs in overview

Source/devtools/front_end/timeline/TimelineEventOverview.js

Index: Source/devtools/front_end/timeline/TimelineEventOverview.js
diff --git a/Source/devtools/front_end/timeline/TimelineEventOverview.js b/Source/devtools/front_end/timeline/TimelineEventOverview.js
index fab00196003aa5467adafda490a4ad74443d1c18..0830decad67681bc4706765ad9c719f86f38c467 100644
--- a/Source/devtools/front_end/timeline/TimelineEventOverview.js
+++ b/Source/devtools/front_end/timeline/TimelineEventOverview.js
@@ -254,13 +254,11 @@ WebInspector.TimelineEventOverview.Network.prototype = {
 /**
  * @constructor
  * @extends {WebInspector.TimelineEventOverview}
- * @param {string} id
- * @param {string} title
  * @param {!WebInspector.TimelineModel} model
  */
-WebInspector.TimelineEventOverview.Thread = function(id, title, model)
+WebInspector.TimelineEventOverview.CPUActivity = function(model)
 {
-    WebInspector.TimelineEventOverview.call(this, id, title, model)
+    WebInspector.TimelineEventOverview.call(this, "cpu-activity", WebInspector.UIString("CPU"), model);
     this._fillStyles = {};
     var categories = WebInspector.TimelineUIUtils.categories();
     for (var category in categories) {
@@ -268,9 +266,10 @@ WebInspector.TimelineEventOverview.Thread = function(id, title, model)
         categories[category].addEventListener(WebInspector.TimelineCategory.Events.VisibilityChanged, this._onCategoryVisibilityChanged, this);
     }
     this._disabledCategoryFillStyle = "hsl(0, 0%, 67%)";
+    this._backgroundCanvas = this.element.createChild("canvas", "fill background");
 }
 
-WebInspector.TimelineEventOverview.Thread.prototype = {
+WebInspector.TimelineEventOverview.CPUActivity.prototype = {
     /**
      * @override
      */
@@ -296,29 +295,22 @@ WebInspector.TimelineEventOverview.Thread.prototype = {
         return category.hidden ? this._disabledCategoryFillStyle : this._fillStyles[category.name];
     },
 
-    __proto__: WebInspector.TimelineEventOverview.prototype
-}
-
-/**
- * @constructor
- * @extends {WebInspector.TimelineEventOverview.Thread}
- * @param {!WebInspector.TimelineModel} model
- */
-WebInspector.TimelineEventOverview.MainThread = function(model)
-{
-    WebInspector.TimelineEventOverview.Thread.call(this, "main-thread", WebInspector.UIString("CPU"), model)
-}
+    /**
+     * @override
+     */
+    resetCanvas: function()
+    {
+        WebInspector.TimelineEventOverview.prototype.resetCanvas.call(this);
+        this._backgroundCanvas.width = this.element.clientWidth * window.devicePixelRatio;
+        this._backgroundCanvas.height = this.element.clientHeight * window.devicePixelRatio;
+    },
 
-WebInspector.TimelineEventOverview.MainThread.prototype = {
     /**
      * @override
      */
     update: function()
     {
         WebInspector.TimelineEventOverview.prototype.update.call(this);
-        var events = this._model.mainThreadEvents();
-        if (!events.length)
-            return;
         var /** @const */ quantSizePx = 4 * window.devicePixelRatio;
         var height = this._canvas.height;
         var baseLine = height;
@@ -326,8 +318,7 @@ WebInspector.TimelineEventOverview.MainThread.prototype = {
         var timeSpan = this._model.maximumRecordTime() - timeOffset;
         var scale = this._canvas.width / timeSpan;
         var quantTime = quantSizePx / scale;
-        var quantizer = new WebInspector.Quantizer(timeOffset, quantTime, drawSample.bind(this));
-        var ctx = this._context;
+        var quantizer;
         var x = 0;
         var categories = WebInspector.TimelineUIUtils.categories();
         var categoryOrder = ["idle", "loading", "painting", "rendering", "scripting", "other"];
@@ -338,6 +329,11 @@ WebInspector.TimelineEventOverview.MainThread.prototype = {
             categories[categoryOrder[i]]._overviewIndex = i;
         var categoryIndexStack = [];
 
+        var ctx = this._backgroundCanvas.getContext("2d");
+        this._model.virtualThreads().forEach(function (thread) { drawThreadEvents.call(this, thread.events); }, this);

[caseq, 2015/08/25 01:37:56]

extract a named function?

[alph, 2015/08/25 17:29:26]

Done.

+        ctx = this._context;

[caseq, 2015/08/25 01:37:56]

can we pass this explicitly rather than swap the contexts on the go?

[alph, 2015/08/25 17:29:26]

Done.

+        drawThreadEvents.call(this, this._model.mainThreadEvents());
+
         /**
          * @param {!Array<number>} counters
          * @this {WebInspector.TimelineEventOverview}
@@ -374,11 +370,21 @@ WebInspector.TimelineEventOverview.MainThread.prototype = {
             quantizer.appendInterval(e.endTime, categoryIndexStack.pop());
         }
 
-        WebInspector.TimelineModel.forEachEvent(events, onEventStart, onEventEnd);
-        quantizer.appendInterval(timeOffset + timeSpan + quantTime, idleIndex);  // Kick drawing the last bucket.
+        /**
+         * @param {!Array<!WebInspector.TracingModel.Event>} events
+         * @this {WebInspector.TimelineEventOverview}
+         */
+        function drawThreadEvents(events)
+        {
+            quantizer = new WebInspector.Quantizer(timeOffset, quantTime, drawSample.bind(this));
+            x = 0;
+            categoryIndexStack = [];

[caseq, 2015/08/25 01:37:56]

The above three look scary and puzzling, too!

[alph, 2015/08/25 17:29:26]

Done.

+            WebInspector.TimelineModel.forEachEvent(events, onEventStart, onEventEnd);
+            quantizer.appendInterval(timeOffset + timeSpan + quantTime, idleIndex);  // Kick drawing the last bucket.
+        }
     },
 
-    __proto__: WebInspector.TimelineEventOverview.Thread.prototype
+    __proto__: WebInspector.TimelineEventOverview.prototype
 }
 
 /**