WebUILoginView: Return whether accelerator was handled.

Bug: 1126602
Change-Id: I5dc0c71e08773f1f30b3714299ccf6366099c869
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2426494
Commit-Queue: Roman Aleksandrov <raleksandrov@google.com>
Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809982}

chrome/browser/chromeos/login/ui/webui_login_view.cc

@@ -238,7 +238,7 @@ bool WebUILoginView::AcceleratorPressed(const ui::Accelerator& accelerator) {
   if (entry == accel_map_.end())
     return false;
   if (controller_)
-    controller_->HandleAccelerator(entry->second);
+    return controller_->HandleAccelerator(entry->second);
   return false;
 }