Web MIDI: introduce WebMIDIClient API to request a permission

public/platform/WebMIDIAccessorClient.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 22 matching lines @@
 
 #include "WebString.h"
 
 namespace WebKit {
 
 class WebMIDIAccessorClient {
 public:
     virtual void didAddInputPort(const WebString& id, const WebString& manufacturer, const WebString& name, const WebString& version) = 0;
     virtual void didAddOutputPort(const WebString& id, const WebString& manufacturer, const WebString& name, const WebString& version) = 0;
 
     virtual void didAllowAccess() = 0;

[Chris Rogers, 2013/07/10 23:05:48]

Now that permissions is being handled in another place, didAllowAccess() should
probably be re-named to something like "didAddPorts()" or "didStartSession()" or
something which doesn't have the word "allow" in it.

Seems ok to add this as a TODO for now.

[Takashi Toyoshima, 2013/07/10 23:52:38]

Renamed to didStartSession.

+
+    // FIXME: Remove this obsoleted API. Now access permission is handled though the WebMIDIClient API.
+    // Only didAllowAccess() is used to notice the completion of adding all ports.
     virtual void didBlockAccess() = 0;
 
     // |timeStamp| is in milliseconds according to the Web MIDI API.
     virtual void didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp) = 0;
 
 protected:
     virtual ~WebMIDIAccessorClient() { }
 };
 
 } // namespace WebKit
 
 #endif // WebMIDIAccessorClient_h