Web Share: Refactor Mojo interface to now return an enum error.

third_party/WebKit/LayoutTests/webshare/share-error.html

Index: third_party/WebKit/LayoutTests/webshare/share-error.html
diff --git a/third_party/WebKit/LayoutTests/webshare/share-error.html b/third_party/WebKit/LayoutTests/webshare/share-error.html
index a59ffc6691805f1466d10d00c51f30774e5d647d..c1697e9b5a2084068304b1d67d6fdf4418fcf3cb 100644
--- a/third_party/WebKit/LayoutTests/webshare/share-error.html
+++ b/third_party/WebKit/LayoutTests/webshare/share-error.html
@@ -6,10 +6,20 @@
 <script>
 
 share_test((t, mock) => {
-  mock.pushShareResult('the title', 'the message', 'data:the url', 'error from browser');
+  mock.pushShareResult('the title', 'the message', 'data:the url',
+                       ShareError.CANCELED);
+  // promise_rejects doesn't test the exception message, so just undefined.
   return callWithKeyDown(() => promise_rejects(
-      t, new DOMException('error from browser', 'AbortError'),
+      t, new DOMException(undefined, 'AbortError'),
       navigator.share({title: 'the title', text: 'the message', url: 'data:the url'})));
-}, 'share with browser-side error');
+}, 'share with user cancellation');
+
+share_test((t, mock) => {
+  mock.pushShareResult('the title', 'the message', 'data:the url',
+                       ShareError.INVALID_TEMPLATE);
+  return callWithKeyDown(() => promise_rejects(
+      t, new DOMException(undefined, 'AbortError'),
+      navigator.share({title: 'the title', text: 'the message', url: 'data:the url'})));
+}, 'share with invalid url template');
 
 </script>