Add offscreen-canvas to the list of wpt directories to skip.

third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.clearRect.basic.worker.js

Index: third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.clearRect.basic.worker.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.clearRect.basic.worker.js b/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.clearRect.basic.worker.js
deleted file mode 100644
index eb0ae4efe0c7c45370d332be42e0b47c71088bc9..0000000000000000000000000000000000000000
--- a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.clearRect.basic.worker.js
+++ /dev/null
@@ -1,23 +0,0 @@
-// DO NOT EDIT! This test has been generated by tools/gentest.py.
-// OffscreenCanvas test in a worker:2d.clearRect.basic
-// Description:clearRect clears to transparent black
-// Note:
-
-importScripts("/resources/testharness.js");
-importScripts("/common/canvas-tests.js");
-
-var t = async_test("clearRect clears to transparent black");
-t.step(function() {
-
-var offscreenCanvas = new OffscreenCanvas(100, 50);
-var ctx = offscreenCanvas.getContext('2d');
-
-ctx.fillStyle = '#f00';
-ctx.fillRect(0, 0, 100, 50);
-ctx.clearRect(0, 0, 100, 50);
-_assertPixel(offscreenCanvas, 50,25, 0,0,0,0, "50,25", "0,0,0,0");
-
-t.done();
-
-});
-done();