DevTools: Timeline warning colors should scale with severity.

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

Index: third_party/WebKit/Source/devtools/front_end/timeline/TimelineEventOverview.js
diff --git a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineEventOverview.js b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineEventOverview.js
index 18c519f991c79a99b35a34fbef31934127bb468f..e9de2646a6659fc820f3885b2c30e88c789c21d0 100644
--- a/third_party/WebKit/Source/devtools/front_end/timeline/TimelineEventOverview.js
+++ b/third_party/WebKit/Source/devtools/front_end/timeline/TimelineEventOverview.js
@@ -389,8 +389,7 @@ WebInspector.TimelineEventOverview.Responsiveness.prototype = {
         var scale = this._canvas.width / timeSpan;
         var frames = this._frameModel.frames();
         var ctx = this._context;
-        var fillPath = new Path2D();
-        var markersPath = new Path2D();
+
         for (var i = 0; i < frames.length; ++i) {
             var frame = frames[i];
             if (!frame.hasWarnings())
@@ -405,11 +404,6 @@ WebInspector.TimelineEventOverview.Responsiveness.prototype = {
             paintWarningDecoration(events[i].startTime, events[i].duration);
         }
 
-        ctx.fillStyle = "hsl(0, 80%, 90%)";
-        ctx.strokeStyle = "red";
-        ctx.lineWidth = 2 * window.devicePixelRatio;
-        ctx.fill(fillPath);
-        ctx.stroke(markersPath);
 
         /**
          * @param {number} time
@@ -419,9 +413,18 @@ WebInspector.TimelineEventOverview.Responsiveness.prototype = {
         {
             var x = Math.round(scale * (time - timeOffset));
             var w = Math.round(scale * duration);
-            fillPath.rect(x, 0, w, height);
-            markersPath.moveTo(x + w, 0);
-            markersPath.lineTo(x + w, height);
+            var markersPath = new Path2D();
+
+            var overage = duration - 16;

[caseq, 2016/08/16 18:37:16]

should we do it just for frames perhaps? how does it work on lots of short
layout thrashing events?

+            var intensity = Number.constrain(overage / (30 + overage), 0, 1).toFixed(3);
+            ctx.fillStyle = `hsla(0, 80%, 85%, ${intensity})`;
+            ctx.fillRect(x, 0, w, height);
+
+            markersPath.moveTo(x, 0);
+            markersPath.lineTo(x + w, 0);
+            ctx.strokeStyle = `hsla(0, 80%, 45%, ${intensity})`;
+            ctx.lineWidth = 2 * window.devicePixelRatio;
+            ctx.stroke(markersPath);
         }
     },