Implement WebGL's commit on the main thread

third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-commit-invalid-call.html

 <!DOCTYPE>
 <script src="../../resources/testharness.js"></script>
 <script src="../../resources/testharnessreport.js"></script>
 <script id="myWorker" type="text/worker">
 self.onmessage = function(e) {
     var offscreenCanvas = new OffscreenCanvas(50, 50);
     var offscreen2d = offscreenCanvas.getContext("2d");
     try {
         offscreen2d.commit();
         self.postMessage("NoError");
     } catch (ex) {
         self.postMessage(ex.name);
     }
 };
 </script>
 <script>
 function makeWorker(script) {
    var blob = new Blob([script]);
    return new Worker(URL.createObjectURL(blob));
 }
 
-
 test(function() {
     var offscreenCanvas = new OffscreenCanvas(50, 50);
     var offscreen2d = offscreenCanvas.getContext("2d");
     assert_throws("InvalidStateError", function () {
         offscreen2d.commit();
     });
 }, "Calling OffscreenCanvas.commit() on main without transferControlToOffscreen throws exception.");
 
+test(function() {
+    var offscreenCanvas = new OffscreenCanvas(50, 50);
+    var gl = offscreenCanvas.getContext("webgl");
+    gl.clearColor(1.0, 0.0, 0.0, 1.0);
+    gl.clear(gl.COLOR_BUFFER_BIT);
+    assert_throws("InvalidStateError", function() {
+        gl.commit();
+    });
+}, "Calling WebGL's commit() on main without transferControlToOffscreen throws exception.");
+
+test(function() {
+    var canvas = document.createElement('canvas');
+    canvas.width = 50;
+    canvas.height = 50;
+    var gl = canvas.getContext("webgl");
+    gl.clearColor(1.0, 0.0, 0.0, 1.0);
+    gl.clear(gl.COLOR_BUFFER_BIT);
+    assert_throws("InvalidStateError", function() {
+        gl.commit();
+    });
+}, "Calling WebGL's commit() on main without a OffscreenCanvas throws exception.");
+
 async_test(function() {
     var worker = makeWorker(document.getElementById("myWorker").textContent);
     worker.onmessage = this.step_func(function (e) {
         assert_equals(e.data, "InvalidStateError", "Expected exception on worker but receives " + e.data);
         this.done();
     });
     worker.postMessage("");
 }, "Calling OffscreenCanvas.commit() on worker without transferControlToOffscreen throws exception.");
 
 
 
 </script>