Web MIDI: allow to show an infobar for permission requests from local files

chrome/browser/media/chrome_midi_permission_context.cc

Index: chrome/browser/media/chrome_midi_permission_context.cc
diff --git a/chrome/browser/media/chrome_midi_permission_context.cc b/chrome/browser/media/chrome_midi_permission_context.cc
index ae55f9394b4cc3e48bf9ba085daa55818e0dcccc..7f727f80122a0d8499fcbc9dfb44113bfbcb8e5f 100644
--- a/chrome/browser/media/chrome_midi_permission_context.cc
+++ b/chrome/browser/media/chrome_midi_permission_context.cc
@@ -53,7 +53,11 @@ void ChromeMIDIPermissionContext::RequestMIDISysExPermission(
   const PermissionRequestID id(render_process_id, render_view_id, bridge_id);
 
   GURL embedder = web_contents->GetURL();
-  if (!requesting_frame.is_valid() || !embedder.is_valid()) {
+  // |requesting_frame| can be empty and invalid when the frame is a local
+  // file. Here local files should be granted to show an infobar.
+  // Any user's action will not be stored to content settings data base.
+  if ((!requesting_frame.is_valid() && !requesting_frame.is_empty()) ||
+      !embedder.is_valid()) {
     LOG(WARNING) << "Attempt to use MIDI sysex from an invalid URL: "
                  << requesting_frame << "," << embedder
                  << " (Web MIDI is not supported in popups)";