Get rid of base::SharedMemory::NULLHandle();

ppapi/proxy/ppb_audio_proxy.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/proxy/ppb_audio_proxy.h"
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/threading/simple_thread.h"
 #include "build/build_config.h"
@@ skipping 231 matching lines @@
     enter.object()->StartPlayback();
   else
     enter.object()->StopPlayback();
 }
 
 void PPB_Audio_Proxy::AudioChannelConnected(
     int32_t result,
     const HostResource& resource) {
   IPC::PlatformFileForTransit socket_handle =
       IPC::InvalidPlatformFileForTransit();
-  base::SharedMemoryHandle shared_memory = base::SharedMemory::NULLHandle();
+  base::SharedMemoryHandle shared_memory;
   uint32_t audio_buffer_length = 0;
 
   int32_t result_code = result;
   if (result_code == PP_OK) {
     result_code = GetAudioConnectedHandles(resource, &socket_handle,
                                            &shared_memory,
                                            &audio_buffer_length);
   }
 
   // Send all the values, even on error. This simplifies some of our cleanup
@@ skipping 68 matching lines @@
     static_cast<Audio*>(enter.object())->SetStreamInfo(
         enter.resource()->pp_instance(), handle.shmem(), handle.size(),
         IPC::PlatformFileForTransitToPlatformFile(socket_handle.descriptor()),
         config.object()->GetSampleRate(),
         config.object()->GetSampleFrameCount());
   }
 }
 
 }  // namespace proxy
 }  // namespace ppapi