Clean up the PermissionInfoBarDelegate hierarchy.

chrome/browser/media/midi_permission_infobar_delegate_android.h

Index: chrome/browser/media/midi_permission_infobar_delegate_android.h
diff --git a/chrome/browser/media/midi_permission_infobar_delegate_android.h b/chrome/browser/media/midi_permission_infobar_delegate_android.h
index e0e6f51e526f7dae0fa05fe9cd3ea171506a2a9e..1644b4ec883752c246cfb633e31f55ef58209bb7 100644
--- a/chrome/browser/media/midi_permission_infobar_delegate_android.h
+++ b/chrome/browser/media/midi_permission_infobar_delegate_android.h
@@ -8,8 +8,7 @@
 #include <string>
 
 #include "base/macros.h"
-#include "chrome/browser/permissions/permission_infobar_delegate.h"
-#include "components/content_settings/core/common/content_settings_types.h"
+#include "chrome/browser/permissions/single_permission_infobar_delegate.h"
 
 class GURL;
 class InfoBarService;
@@ -17,7 +16,8 @@ class InfoBarService;
 // MidiPermissionInfoBarDelegateAndroids are created by the
 // MidiPermissionContext to control the display and handling of MIDI permission
 // infobars to the user.
-class MidiPermissionInfoBarDelegateAndroid : public PermissionInfobarDelegate {
+class MidiPermissionInfoBarDelegateAndroid
+    : public SinglePermissionInfoBarDelegate {
  public:
   // Creates a MIDI permission infobar and delegate and adds the infobar to
   // |infobar_service|.  Returns the infobar if it was successfully added.
@@ -39,8 +39,6 @@ class MidiPermissionInfoBarDelegateAndroid : public PermissionInfobarDelegate {
   int GetIconId() const override;
   int GetMessageResourceId() const override;
 
-  GURL requesting_frame_;
-
   DISALLOW_COPY_AND_ASSIGN(MidiPermissionInfoBarDelegateAndroid);
 };