Add rendering context and rendering 2D context to OffscreenCanvas

third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-getContext2D-in-worker.html

Index: third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-getContext2D-in-worker.html
diff --git a/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-constructor-in-worker.html b/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-getContext2D-in-worker.html
similarity index 53%
copy from third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-constructor-in-worker.html
copy to third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-getContext2D-in-worker.html
index b87006d34ee0a8a45aa463d32a94ce20edd079f5..5d0c326866a772359de2c957dfe471fd8159715d 100644
--- a/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-constructor-in-worker.html
+++ b/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-getContext2D-in-worker.html
@@ -5,20 +5,18 @@
 <script id="myWorker" type="text/worker">
 self.onmessage = function(e) {
   var aCanvas = new OffscreenCanvas(50, 50);
-  self.postMessage({version:'first', width:aCanvas.width, height:aCanvas.height});
-
-  aCanvas.width = 100;
-  aCanvas.height = 100;
-  self.postMessage({version:'second', width:aCanvas.width, height:aCanvas.height});
+  try {
+     var ctx = aCanvas.getContext('2d');
+     self.postMessage({outcome:"success", errorMessage:""});
+  } catch (e) {
+     self.postMessage({outcome:"error", errorMessage:e});
+  }
 };
 </script>
 
 <script>
 jsTestIsAsync = true;
-description("Tests that the OffscreenCanvas can be constructed on a worker thread.");
-
-var width;
-var height;
+description("Tests that the 2D context of OffscreenCanvas can be constructed on a worker thread.");
 
 function makeWorker(script) {
   var blob = new Blob([script]);
@@ -26,22 +24,18 @@ function makeWorker(script) {
 }
 
 function handleMessageFromWorker(msg) {
-  width = msg.data.width;
-  height = msg.data.height;
-  switch (msg.data.version) {
-    case 'first':
-      shouldBe('width', '50');
-      shouldBe('height', '50');
+  switch (msg.data.outcome) {
+    case 'success':
+      testPassed("getContext('2d') does not thrown.");
       break;
-    case 'second':
-      shouldBe('width', '100');
-      shouldBe('height', '100');
-      finishJSTest();
+    case 'error':
+      testFailed(msg.data.errorMessage);
       break;
     default:
       testFailed("Unexpected failure");
       break;
   }
+  finishJSTest();
 }
 
 var worker = makeWorker(document.getElementById('myWorker').textContent);