Web MIDI: introduce WebMIDIClient API to request a permission

Source/core/platform/midi/MIDIAccessorClient.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 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef MIDIAccessorClient_h
 #define MIDIAccessorClient_h
 
 #include "wtf/Forward.h"
 
 namespace WebCore {
+class SecurityOrigin;
 
 class MIDIAccessorClient {
 public:
+    virtual SecurityOrigin* securityOrigin() const = 0;
+
     virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version) = 0;
     virtual void didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version) = 0;
 
     virtual void didAllowAccess() = 0;
     virtual void didBlockAccess() = 0;
     virtual void didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp) = 0;
 };
 
 } // namespace WebCore
 
 #endif // MIDIAccessorClient_h