Remove error.message in SharedWorker WPT (web-platform-tests#21287)

error of SharedWorker is |Event| type or |ErrorEvent|.
This CL removes error.message because |Event| doesn't have |message| property.
https://html.spec.whatwg.org/multipage/indices.html#event-error

Bug: 1043634
Change-Id: Id7ff6b4222c56b770457731694f07fd850504681
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2011621
Reviewed-by: Hiroki Nakagawa <[email protected]>
Commit-Queue: Eriko Kurimoto <[email protected]>
Cr-Commit-Position: refs/heads/master@{#733909}

workers/modules/dedicated-worker-import-blob-url.any.js

@@ -13,7 +13,11 @@ function import_blob_url_test(testCase) {
     worker.postMessage('Send message for tests from main script.');
     const msgEvent = await new Promise((resolve, reject) => {
       worker.onmessage = resolve;
-      worker.onerror = (error) => reject(error && error.message);
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
     });
     assert_array_equals(msgEvent.data, testCase.expectation);
   }, testCase.description);

workers/modules/dedicated-worker-import-failure.html

@@ -38,7 +38,11 @@
   worker.postMessage(scriptURL);
   const msg_event = await new Promise((resolve, reject) => {
     worker.onmessage = resolve;
-    worker.onerror = (error) => reject(error && error.message);
+    worker.onerror = error => {
+      const msg = error instanceof ErrorEvent ? error.message
+                                              : 'unknown error';
+      reject(msg);
+    };
   });
   assert_equals(msg_event.data, 'TypeError');
 }, 'Dynamic import for non-existent script should throw an exception.');

workers/modules/dedicated-worker-import-meta.html

@@ -9,7 +9,11 @@
   const worker = new Worker(script_url, { type: 'module' });
   return new Promise((resolve, reject) => {
         worker.onmessage = resolve;
-        worker.onerror = (error) => reject(error && error.message);
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
       })
       .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
 }, 'Test import.meta.url on the top-level module script.');
@@ -21,7 +25,11 @@
   worker.postMessage('./' + script_url);
   return new Promise((resolve, reject) => {
         worker.onmessage = resolve;
-        worker.onerror = (error) => reject(error && error.message);
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
       })
       .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
 }, 'Test import.meta.url on the imported module script.');
@@ -34,7 +42,11 @@
 
   return new Promise((resolve, reject) => {
         worker.onmessage = resolve;
-        worker.onerror = (error) => reject(error && error.message);
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
       })
       .then(msg_event => assert_true(msg_event.data.endsWith(script_url)))
       .then(() => {

workers/modules/dedicated-worker-import.any.js

@@ -9,7 +9,11 @@ function import_test(testCase) {
     worker.postMessage('Send message for tests from main script.');
     const msgEvent = await new Promise((resolve, reject) => {
       worker.onmessage = resolve;
-      worker.onerror = (error) => reject(error && error.message);
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
     });
     assert_array_equals(msgEvent.data, testCase.expectation);
   }, testCase.description);

workers/modules/shared-worker-import-blob-url.any.js

@@ -14,7 +14,11 @@ function import_blob_url_test(testCase) {
     worker.port.postMessage('Send message for tests from main script.');
     const msgEvent = await new Promise((resolve, reject) => {
       worker.port.onmessage = resolve;
-      worker.onerror = (error) => reject(error && error.message);
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
     });
     assert_array_equals(msgEvent.data, testCase.expectation);
   }, testCase.description);

workers/modules/shared-worker-import.any.js

@@ -10,7 +10,11 @@ function import_test(testCase) {
     worker.port.postMessage('Send message for tests from main script.');
     const msgEvent = await new Promise((resolve, reject) => {
       worker.port.onmessage = resolve;
-      worker.onerror = (error) => reject(error && error.message);
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
     });
     assert_array_equals(msgEvent.data, testCase.expectation);
   }, testCase.description);