DevTools: remove color generator from timeline flame chart.

Source/devtools/front_end/TimelineEventOverview.js

 /*
  * Copyright (C) 2013 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 29 matching lines @@
     this.element.id = "timeline-overview-events";
 
     this._fillStyles = {};
     var categories = WebInspector.TimelineUIUtils.categories();
     for (var category in categories) {
         this._fillStyles[category] = WebInspector.TimelineUIUtils.createFillStyleForCategory(this._context, 0, WebInspector.TimelineEventOverview._stripGradientHeight, categories[category]);
         categories[category].addEventListener(WebInspector.TimelineCategory.Events.VisibilityChanged, this._onCategoryVisibilityChanged, this);
     }
 
     this._disabledCategoryFillStyle = WebInspector.TimelineUIUtils.createFillStyle(this._context, 0, WebInspector.TimelineEventOverview._stripGradientHeight,
-        "rgb(218, 218, 218)", "rgb(170, 170, 170)", "rgb(143, 143, 143)");
+        "hsl(0, 0%, 85%)", "hsl(0, 0%, 67%)", "hsl(0, 0%, 56%)");
 
     this._disabledCategoryBorderStyle = "rgb(143, 143, 143)";
 }
 
 /** @const */
 WebInspector.TimelineEventOverview._numberOfStrips = 3;
 
 /** @const */
 WebInspector.TimelineEventOverview._stripGradientHeight = 120;
 
@@ skipping 70 matching lines @@
         this._context.scale(1, innerStripHeight / WebInspector.TimelineEventOverview._stripGradientHeight);
         this._context.fillStyle = category.hidden ? this._disabledCategoryFillStyle : this._fillStyles[category.name];
         this._context.fillRect(0, 0, width, WebInspector.TimelineEventOverview._stripGradientHeight);
         this._context.strokeStyle = category.hidden ? this._disabledCategoryBorderStyle : category.borderColor;
         this._context.strokeRect(0, 0, width, WebInspector.TimelineEventOverview._stripGradientHeight);
         this._context.restore();
     },
 
     __proto__: WebInspector.TimelineOverviewBase.prototype
 }