Update MidiDispatcher to use Mojo Permission Service.

content/renderer/media/midi_dispatcher.h

Index: content/renderer/media/midi_dispatcher.h
diff --git a/content/renderer/media/midi_dispatcher.h b/content/renderer/media/midi_dispatcher.h
index cfa77ee9b7b91b496a941e935d079fd30c0f4d56..65a11d117b70d550144e58f5012665fa8785697d 100644
--- a/content/renderer/media/midi_dispatcher.h
+++ b/content/renderer/media/midi_dispatcher.h
@@ -6,6 +6,7 @@
 #define CONTENT_RENDERER_MEDIA_MIDI_DISPATCHER_H_
 
 #include "base/id_map.h"
+#include "content/common/permission_service.mojom.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "third_party/WebKit/public/web/WebMIDIClient.h"
 
@@ -17,9 +18,8 @@ namespace content {
 
 // MidiDispatcher implements WebMIDIClient to handle permissions for using
 // system exclusive messages.
-// It works as RenderFrameObserver to handle IPC messages between
-// MidiDispatcherHost owned by WebContents since permissions are managed in
-// the browser process.
+// It works as RenderFrameObserver to keep a 1:1 relationship with a RenderFrame
+// and make sure it has the same life cycle.
 class MidiDispatcher : public RenderFrameObserver,
                        public blink::WebMIDIClient {
  public:
@@ -27,9 +27,6 @@ class MidiDispatcher : public RenderFrameObserver,
   virtual ~MidiDispatcher();
 
  private:
-  // RenderFrameObserver implementation.
-  bool OnMessageReceived(const IPC::Message& message) override;
-
   // blink::WebMIDIClient implementation.
   virtual void requestSysexPermission(
       const blink::WebMIDIPermissionRequest& request);
@@ -37,7 +34,7 @@ class MidiDispatcher : public RenderFrameObserver,
       const blink::WebMIDIPermissionRequest& request);
 
   // Permission for using system exclusive messages has been set.
-  void OnSysExPermissionApproved(int client_id, bool is_allowed);
+  void OnSysExPermissionSet(int request_id, PermissionStatus status);
 
   // Each WebMIDIPermissionRequest object is valid until
   // cancelSysexPermissionRequest() is called with the object, or used to call
@@ -45,6 +42,8 @@ class MidiDispatcher : public RenderFrameObserver,
   typedef IDMap<blink::WebMIDIPermissionRequest, IDMapOwnPointer> Requests;
   Requests requests_;
 
+  PermissionServicePtr permission_service_;
+
   DISALLOW_COPY_AND_ASSIGN(MidiDispatcher);
 };