Increase tolerance for the color checks in createImageBitmap-drawImag…

…e.html.

The difference in WebKit on macOS can be up to 8.

2dcontext/imagebitmap/createImageBitmap-drawImage.html

@@ -12,7 +12,7 @@
 <script>
 function testCanvasDisplayingPattern(canvas, width, height)
 {
-    var tolerance = 5; // for creating ImageBitmap from a video, the tolerance needs to be high
+    var tolerance = 10; // for creating ImageBitmap from a video, the tolerance needs to be high
     const check = (x, y, r, g, b, a) =>
         _assertPixelApprox(canvas, x,y, r,g,b,a, `${x},${y}`, `${r},${g},${b},${a}`, tolerance);
     check(1 * width / 4, 1 * height / 4, 255,0,0,255);