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

third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/compositing/2d.composite.canvas.lighter.worker.js

Index: third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/compositing/2d.composite.canvas.lighter.worker.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/compositing/2d.composite.canvas.lighter.worker.js b/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/compositing/2d.composite.canvas.lighter.worker.js
deleted file mode 100644
index 060c6a3ffa339b95c584f92f4e4d490df4504d8e..0000000000000000000000000000000000000000
--- a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/compositing/2d.composite.canvas.lighter.worker.js
+++ /dev/null
@@ -1,39 +0,0 @@
-// DO NOT EDIT! This test has been generated by tools/gentest.py.
-// OffscreenCanvas test in a worker:2d.composite.canvas.lighter
-// Description:
-// Note:
-
-importScripts("/resources/testharness.js");
-importScripts("/common/canvas-tests.js");
-
-var t = async_test("");
-t.step(function() {
-
-var offscreenCanvas = new OffscreenCanvas(100, 50);
-var ctx = offscreenCanvas.getContext('2d');
-
-
-var offscreenCanvas2 = new OffscreenCanvas(offscreenCanvas.width, offscreenCanvas.height);
-var ctx2 = offscreenCanvas2.getContext('2d');
-var promise = new Promise(function(resolve, reject) {
-    var xhr = new XMLHttpRequest();
-    xhr.open("GET", '/images/yellow75.png');
-    xhr.responseType = 'blob';
-    xhr.send();
-    xhr.onload = function() {
-        resolve(xhr.response);
-    };
-});
-promise.then(function(response) {
-    ctx2.drawImage(response, 0, 0);
-    ctx.fillStyle = 'rgba(0, 255, 255, 0.5)';
-    ctx.fillRect(0, 0, 100, 50);
-    ctx.globalCompositeOperation = 'lighter';
-    ctx.drawImage(offscreenCanvas2, 0, 0);
-    _assertPixelApprox(offscreenCanvas, 50,25, 191,255,128,255, "50,25", "191,255,128,255", 5);
-});
-
-t.done();
-
-});
-done();