[Extensions] Make Event::restrict_to_browser_context const.

chrome/browser/chromeos/file_manager/file_browser_handlers.cc

Index: chrome/browser/chromeos/file_manager/file_browser_handlers.cc
diff --git a/chrome/browser/chromeos/file_manager/file_browser_handlers.cc b/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
index 0dee05cbbea233542474fe75f99c1708a2d9a102..381dc8f28070926f2424be798060a2ea5023a600 100644
--- a/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
+++ b/chrome/browser/chromeos/file_manager/file_browser_handlers.cc
@@ -408,10 +408,9 @@ void FileBrowserHandlerExecutor::SetupPermissionsAndDispatchEvent(
 
   details->Set("entries", std::move(file_entries));
   event_args->Append(std::move(details));
-  std::unique_ptr<extensions::Event> event(new extensions::Event(
+  auto event = base::MakeUnique<extensions::Event>(
       extensions::events::FILE_BROWSER_HANDLER_ON_EXECUTE,
-      "fileBrowserHandler.onExecute", std::move(event_args)));
-  event->restrict_to_browser_context = profile_;
+      "fileBrowserHandler.onExecute", std::move(event_args), profile_);
   router->DispatchEventToExtension(extension_->id(), std::move(event));
 
   ExecuteDoneOnUIThread(true);