Implement suspend() and resume() for OfflineAudioContext

Source/modules/webaudio/OfflineAudioContext.idl

 /*
  * 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:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 [
     Conditional=WEB_AUDIO,
     Constructor(unsigned long numberOfChannels, unsigned long numberOfFrames, float sampleRate),
     ConstructorCallWith=ExecutionContext,
     RaisesException=Constructor,
     NoInterfaceObject,
 ] interface OfflineAudioContext : AudioContext {
     // Offline rendering
     attribute EventHandler oncomplete;
     [CallWith=ScriptState,ImplementedAs=startOfflineRendering] Promise<AudioBuffer> startRendering();
+    [CallWith=ScriptState,ImplementedAs=suspendOfflineRendering] Promise<void> suspend(double suspendTime);

[hongchan, 2015/06/12 17:51:44]

Should the use counter be a part of this CL as well?

[Raymond Toy, 2015/06/12 17:58:22]

I would do it now.

+    [CallWith=ScriptState,ImplementedAs=resumeOfflineRendering] Promise<void> resume();
 };