Import wpt@3c8896ae408c8fd594979da7c99970029e7856a7

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

+// DO NOT EDIT! This test has been generated by tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.composite.globalAlpha.imagepattern
+// 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');
+
+ctx.fillStyle = '#0f0';
+ctx.fillRect(0, 0, 100, 50);
+var promise = new Promise(function(resolve, reject) {
+    var xhr = new XMLHttpRequest();
+    xhr.open("GET", '/images/red.png');
+    xhr.responseType = 'blob';
+    xhr.send();
+    xhr.onload = function() {
+        resolve(xhr.response);
+    };
+});
+promise.then(function(response) {
+    ctx.fillStyle = ctx.createPattern(response, 'no-repeat');
+    ctx.globalAlpha = 0.01; // avoid any potential alpha=0 optimisations
+    ctx.fillRect(0, 0, 100, 50);
+    _assertPixelApprox(offscreenCanvas, 50,25, 2,253,0,255, "50,25", "2,253,0,255", 2);
+});
+
+t.done();
+
+});
+done();