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

third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/transformations/2d.transformation.scale.negative.worker.js

Index: third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/transformations/2d.transformation.scale.negative.worker.js
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/transformations/2d.transformation.scale.negative.worker.js b/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/transformations/2d.transformation.scale.negative.worker.js
deleted file mode 100644
index 27d6de0c5304c32dbfb4103ccec017d910c18dd8..0000000000000000000000000000000000000000
--- a/third_party/WebKit/LayoutTests/imported/wpt/offscreen-canvas/transformations/2d.transformation.scale.negative.worker.js
+++ /dev/null
@@ -1,33 +0,0 @@
-// DO NOT EDIT! This test has been generated by tools/gentest.py.
-// OffscreenCanvas test in a worker:2d.transformation.scale.negative
-// Description:scale() with negative scale factors works
-// Note:
-
-importScripts("/resources/testharness.js");
-importScripts("/common/canvas-tests.js");
-
-var t = async_test("scale() with negative scale factors works");
-t.step(function() {
-
-var offscreenCanvas = new OffscreenCanvas(100, 50);
-var ctx = offscreenCanvas.getContext('2d');
-
-ctx.fillStyle = '#f00';
-ctx.fillRect(0, 0, 100, 50);
-ctx.save();
-ctx.scale(-1, 1);
-ctx.fillStyle = '#0f0';
-ctx.fillRect(-50, 0, 50, 50);
-ctx.restore();
-ctx.save();
-ctx.scale(1, -1);
-ctx.fillStyle = '#0f0';
-ctx.fillRect(50, -50, 50, 50);
-ctx.restore();
-_assertPixel(offscreenCanvas, 25,25, 0,255,0,255, "25,25", "0,255,0,255");
-_assertPixel(offscreenCanvas, 75,25, 0,255,0,255, "75,25", "0,255,0,255");
-
-t.done();
-
-});
-done();