[Devtools] Fix hover issue with darktheme in network

third_party/WebKit/Source/devtools/front_end/ui_lazy/TimelineGrid.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Anthony Ricaud <rik@webkit.org>
  * Copyright (C) 2009 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 79 matching lines @@
       offsets.push(time);
     }
 
     return {offsets: offsets, precision: Math.max(0, -Math.floor(Math.log(gridSliceTime * 1.01) / Math.LN10))};
   }
 
   /**
    * @param {!CanvasRenderingContext2D} context
    * @param {!UI.TimelineGrid.Calculator} calculator
    * @param {number} paddingTop
+   * @param {number} headerHeight
    * @param {number=} freeZoneAtLeft
    */
-  static drawCanvasGrid(context, calculator, paddingTop, freeZoneAtLeft) {
+  static drawCanvasGrid(context, calculator, paddingTop, headerHeight, freeZoneAtLeft) {
     context.save();
     var ratio = window.devicePixelRatio;
     context.scale(ratio, ratio);
     var width = context.canvas.width / window.devicePixelRatio;
     var height = context.canvas.height / window.devicePixelRatio;
     var dividersData = UI.TimelineGrid.calculateDividerOffsets(calculator);
     var dividerOffsets = dividersData.offsets;
     var precision = dividersData.precision;
 
-    context.fillStyle = 'rgba(255, 255, 255, 0.5)';
-    context.fillRect(0, 0, width, 15);
+    context.fillStyle = UI.themeSupport.patchColor('rgba(255, 255, 255, 0.5)', UI.ThemeSupport.ColorUsage.Background);
+    context.fillRect(0, 0, width, headerHeight);
 
-    context.fillStyle = '#333';
-    context.strokeStyle = 'rgba(0, 0, 0, 0.1)';
+    context.fillStyle = UI.themeSupport.patchColor('#333', UI.ThemeSupport.ColorUsage.Foreground);
+    context.strokeStyle = UI.themeSupport.patchColor('rgba(0, 0, 0, 0.1)', UI.ThemeSupport.ColorUsage.Foreground);
     context.textBaseline = 'hanging';
     context.font = '11px ' + Host.fontFamily();
     context.lineWidth = 1;
 
     context.translate(0.5, 0.5);
     const paddingRight = 4;
     freeZoneAtLeft = freeZoneAtLeft || 0;
     for (var i = 0; i < dividerOffsets.length; ++i) {
       var time = dividerOffsets[i];
       var position = calculator.computePosition(time);
@@ skipping 155 matching lines @@
 
   /** @return {number} */
   zeroTime() {},
 
   /** @return {number} */
   maximumBoundary() {},
 
   /** @return {number} */
   boundarySpan() {}
 };