Use multiple shared memory buffers cyclically for audio capture.

content/renderer/pepper/pepper_platform_audio_input_impl.h

Index: content/renderer/pepper/pepper_platform_audio_input_impl.h
===================================================================
--- content/renderer/pepper/pepper_platform_audio_input_impl.h	(revision 186213)
+++ content/renderer/pepper/pepper_platform_audio_input_impl.h	(working copy)
@@ -52,9 +52,11 @@
   virtual void ShutDown() OVERRIDE;
 
   // media::AudioInputIPCDelegate.
-  virtual void OnStreamCreated(base::SharedMemoryHandle handle,
-                               base::SyncSocket::Handle socket_handle,
-                               int length) OVERRIDE;
+  virtual void OnStreamCreated(base::SyncSocket::Handle socket_handle,
+                               int total_handles) OVERRIDE;
+  virtual void OnSharedMemoryCreated(base::SharedMemoryHandle handle,
+                                     int length,
+                                     int index) OVERRIDE;
   virtual void OnVolume(double volume) OVERRIDE;
   virtual void OnStateChanged(
       media::AudioInputIPCDelegate::State state) OVERRIDE;
@@ -96,6 +98,8 @@
   // I/O thread except to send messages and get the message loop.
   scoped_refptr<AudioInputMessageFilter> ipc_;
 
+  base::SyncSocket::Handle socket_handle_;
+
   // Our ID on the MessageFilter. THIS MUST ONLY BE ACCESSED ON THE I/O THREAD
   // or else you could race with the initialize function which sets it.
   int32 stream_id_;