1 files changed, 69 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance/offscreencanvas/context-lost.html b/dom/canvas/test/webgl-conf/checkout/conformance/offscreencanvas/context-lost.html
new file mode 100644
index 0000000000..0568ad229e
--- /dev/null
+++ b/dom/canvas/test/webgl-conf/checkout/conformance/offscreencanvas/context-lost.html
@@ -0,0 +1,69 @@
+<!--
+Copyright (c) 2019 The Khronos Group Inc.
+Use of this source code is governed by an MIT-style license that can be
+found in the LICENSE.txt file.
+-->
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<link rel="stylesheet" href="../../resources/js-test-style.css"/>
+<script src="../../js/js-test-pre.js"></script>
+<script src="../../js/webgl-test-utils.js"></script>
+<script src="../../js/tests/canvas-tests-utils.js"></script>
+<script>
+function init()
+{
+    description("Tests behavior under a lost context for OffscreenCanvas");
+
+    if (!window.OffscreenCanvas) {
+      testPassed("No OffscreenCanvas support");
+      finishTest();
+      return;
+    }
+
+    canvas = new OffscreenCanvas(10, 10);
+    gl = canvas.getContext('webgl');
+
+    // call testValidContext() before checking for the extension, because this is where we check
+    // for the isContextLost() method, which we want to do regardless of the extension's presence.
+    if (!testValidContext()) {
+        testFailed("Some tests failed");
+        finishTest();
+        return;
+    }
+
+    extension = gl.getExtension("WEBGL_lose_context");
+    // need an extension that exposes new API methods.
+    OES_vertex_array_object = gl.getExtension("OES_vertex_array_object");
+    if (extension == null || OES_vertex_array_object == null) {
+        testFailed("Some tests failed");
+        finishTest();
+        return;
+    }
+
+    // We need to initialize |uniformLocation| before losing context.
+    // Otherwise gl.getUniform() when context is lost will throw.
+    uniformLocation = gl.getUniformLocation(program, "tex");
+    extension.loseContext();
+
+    canvas.addEventListener("webglcontextlost", function() {
+        if (testLostContextWithoutRestore()) {
+            testPassed("All tests passed");
+            finishTest();
+            return;
+        } else {
+            testFailed("Some tests failed");
+            finishTest();
+            return;
+        }
+    }, false);
+}
+
+</script>
+</head>
+<body onload="init()">
+<div id="description"></div>
+<div id="console"></div>
+</body>
+</html>