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

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

Index: third_party/WebKit/LayoutTests/webshare/share-arity.html
diff --git a/third_party/WebKit/LayoutTests/webshare/share-arity.html b/third_party/WebKit/LayoutTests/webshare/share-arity.html
index b563ccb0ab19db8b2750b56e9ad6e466e012f3bf..b241bb74a6d4efa50776dfc2a71a64be0eb76a5c 100644
--- a/third_party/WebKit/LayoutTests/webshare/share-arity.html
+++ b/third_party/WebKit/LayoutTests/webshare/share-arity.html
@@ -10,12 +10,12 @@ share_test((t, mock) => {
 }, '0 arguments (promise rejection)');
 
 share_test((t, mock) => {
-  mock.pushShareResult('the title', 'the message', 'data:the url', null);
+  mock.pushShareResult('the title', 'the message', 'data:the url', ShareError.OK);
   return callWithKeyDown(() => navigator.share({title: 'the title', text: 'the message', url: 'data:the url', unused: 'unexpected field'}));
 }, 'extra ShareData field (extra field ignored)');
 
 share_test((t, mock) => {
-  mock.pushShareResult('the title', 'the message', 'data:the url', null);
+  mock.pushShareResult('the title', 'the message', 'data:the url', ShareError.OK);
   return callWithKeyDown(() => navigator.share({title: 'the title', text: 'the message', url: 'data:the url'}, 'more than required'));
 }, '2 arguments (extra argument ignored)');