fix: abort more descriptively for beforeunload (#49011)

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>

shell/browser/api/electron_api_web_contents.cc

@@ -2395,6 +2395,9 @@ void WebContents::LoadURL(const GURL& url,
     return;
   }
 
+  if (web_contents()->NeedToFireBeforeUnloadOrUnloadEvents())
+    pending_unload_url_ = url;
+
   // Discard non-committed entries to ensure we don't re-use a pending entry.
   web_contents()->GetController().DiscardNonCommittedEntries();
   web_contents()->GetController().LoadURLWithParams(params);
@@ -3897,8 +3900,15 @@ void WebContents::RunBeforeUnloadDialog(content::WebContents* web_contents,
                                         content::RenderFrameHost* rfh,
                                         bool is_reload,
                                         DialogClosedCallback callback) {
-  // TODO: asyncify?
   bool default_prevented = Emit("will-prevent-unload");
+
+  if (pending_unload_url_.has_value() && !default_prevented) {
+    Emit("did-fail-load", static_cast<int>(net::ERR_ABORTED),
+         net::ErrorToShortString(net::ERR_ABORTED),
+         pending_unload_url_.value().possibly_invalid_spec(), true);
+    pending_unload_url_.reset();
+  }
+
   std::move(callback).Run(default_prevented, std::u16string());
 }
 

shell/browser/api/electron_api_web_contents.h

@@ -844,6 +844,8 @@ class WebContents final : public ExclusiveAccessContext,
   // that field to ensure the dtor destroys them in the right order.
   raw_ptr<WebContentsZoomController> zoom_controller_ = nullptr;
 
+  std::optional<GURL> pending_unload_url_ = std::nullopt;
+
   // Maps url to file path, used by the file requests sent from devtools.
   typedef std::map<std::string, base::FilePath> PathsMap;
   PathsMap saved_files_;