Web MIDI: introduce WebMIDIClient API to request a permission

public/platform/WebMIDIAccessor.h

Index: public/platform/WebMIDIAccessor.h
diff --git a/public/platform/WebMIDIAccessor.h b/public/platform/WebMIDIAccessor.h
index 119f0b91aa837f0bc673f02c5bea4bdfeaf7412f..07736bb1a0577166e7627bf3b4512632d265ce32 100644
--- a/public/platform/WebMIDIAccessor.h
+++ b/public/platform/WebMIDIAccessor.h
@@ -39,6 +39,9 @@ class WebMIDIAccessor {
 public:
     virtual ~WebMIDIAccessor() { }
 
+    virtual void requestAccess() { }

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

Because access is now being handled in another place, it seems like we need a
better name for this API -- maybe something like "startSession()" or
"getAccess()" or "initializeAccess()" -- anything which doesn't have the word
"request" seems better.

A TODO seems OK for now.

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

Renamed to startSession.

+
+    // FIXME: Remove this obsoleted API. Now access permission is handled though the WebMIDIClient API.
     // |access| is set to true if MIDIOptions.sysex is true. Otherwise false.
     virtual void requestAccess(bool access) { }
     // |timeStamp| is measured in milliseconds as Web MIDI spec defines.