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

BUG=331223

Review URL: https://codereview.chromium.org/122803002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243814 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243814