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

third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.default.worker.js

Index: third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.default.worker.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.default.worker.js b/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.default.worker.js
deleted file mode 100644
index 70bb3a2c4ce68402c4708ea85981fb4762b49b6e..0000000000000000000000000000000000000000
--- a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.default.worker.js
+++ /dev/null
@@ -1,21 +0,0 @@
-// DO NOT EDIT! This test has been generated by tools/gentest.py.
-// OffscreenCanvas test in a worker:size.attributes.default
-// Description:Default width/height when attributes are missing
-// Note:
-
-importScripts("/resources/testharness.js");
-importScripts("/common/canvas-tests.js");
-
-var t = async_test("Default width/height when attributes are missing");
-t.step(function() {
-
-var offscreenCanvas = new OffscreenCanvas(100, 50);
-var ctx = offscreenCanvas.getContext('2d');
-
-_assertSame(offscreenCanvas.width, 100, "offscreenCanvas.width", "100");
-_assertSame(offscreenCanvas.height, 50, "offscreenCanvas.height", "50");
-
-t.done();
-
-});
-done();