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

chrome/browser/webshare/share_service_impl.cc

Index: chrome/browser/webshare/share_service_impl.cc
diff --git a/chrome/browser/webshare/share_service_impl.cc b/chrome/browser/webshare/share_service_impl.cc
index 2ae7404a92dedad8966e1cb75e57836bb168edda..d37470eccab4219caa042ae1d14abca8b744e444 100644
--- a/chrome/browser/webshare/share_service_impl.cc
+++ b/chrome/browser/webshare/share_service_impl.cc
@@ -216,7 +216,7 @@ void ShareServiceImpl::OnPickerClosed(
     const ShareCallback& callback,
     base::Optional<std::string> result) {
   if (!result.has_value()) {
-    callback.Run(base::Optional<std::string>("Share was cancelled"));
+    callback.Run(blink::mojom::ShareError::CANCELED);
     return;
   }
 
@@ -226,8 +226,7 @@ void ShareServiceImpl::OnPickerClosed(
   std::string url_template_filled;
   if (!ReplacePlaceholders(url_template, title, text, share_url,
                            &url_template_filled)) {
-    callback.Run(base::Optional<std::string>(
-        "Error: unable to replace placeholders in url template"));
+    callback.Run(blink::mojom::ShareError::INVALID_TEMPLATE);
     return;
   }
 
@@ -246,5 +245,5 @@ void ShareServiceImpl::OnPickerClosed(
   DCHECK(target.is_valid());
   OpenTargetURL(target);
 
-  callback.Run(base::nullopt);
+  callback.Run(blink::mojom::ShareError::OK);
 }