Web MIDI: refine MIDIAccessor and WebMIDIAccessor APIs

public/platform/Platform.h

 /*
  * Copyright (C) 2012 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 135 matching lines @@
     virtual unsigned audioHardwareOutputChannels() { return 0; }
 
     // Creates a device for audio I/O.
     // Pass in (numberOfInputChannels > 0) if live/local audio input is desired.
     virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*, const WebString& deviceId) { return 0; }
 
     // FIXME: remove deprecated APIs once chromium switches over to new method.
     virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*) { return 0; }
     virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*) { return 0; }
 
+
     // MIDI ----------------------------------------------------------------
 
     // Creates a platform dependent WebMIDIAccessor. MIDIAccessor under platform
     // creates and owns it.
     virtual WebMIDIAccessor* createMIDIAccessor(WebMIDIAccessorClient*) { return 0; }
 
+
     // Blob ----------------------------------------------------------------
 
     // Must return non-null.
     virtual WebBlobRegistry* blobRegistry() { return 0; }
 
 
     // Database ------------------------------------------------------------
 
     // Opens a database file; dirHandle should be 0 if the caller does not need
     // a handle to the directory containing this file
@@ skipping 371 matching lines @@
     // If null, the platform stops providing device motion data to the current listener.
     virtual void setDeviceMotionListener(WebKit::WebDeviceMotionListener*) { }
 
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace WebKit
 
 #endif