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.strokeRect.globalalpha.worker.js

Index: third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.strokeRect.globalalpha.worker.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.strokeRect.globalalpha.worker.js b/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.strokeRect.globalalpha.worker.js
deleted file mode 100644
index f24120034f0f8bc7dff74d94be4338c9cfa75f7b..0000000000000000000000000000000000000000
--- a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/drawing-rectangles-to-the-canvas/2d.strokeRect.globalalpha.worker.js
+++ /dev/null
@@ -1,24 +0,0 @@
-// DO NOT EDIT! This test has been generated by tools/gentest.py.
-// OffscreenCanvas test in a worker:2d.strokeRect.globalalpha
-// Description:strokeRect is affected by globalAlpha
-// Note:
-
-importScripts("/resources/testharness.js");
-importScripts("/common/canvas-tests.js");
-
-var t = async_test("strokeRect is affected by globalAlpha");
-t.step(function() {
-
-var offscreenCanvas = new OffscreenCanvas(100, 50);
-var ctx = offscreenCanvas.getContext('2d');
-
-ctx.globalAlpha = 0;
-ctx.strokeStyle = '#f00';
-ctx.lineWidth = 50;
-ctx.strokeRect(25, 24, 50, 2);
-_assertPixel(offscreenCanvas, 50,25, 0,0,0,0, "50,25", "0,0,0,0");
-
-t.done();
-
-});
-done();