Fix back-to-back StartPlayback/StopPlayback issue in PPAPI IPC proxy

ppapi/shared_impl/ppb_audio_shared.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/shared_impl/ppb_audio_shared.h"
 
 #include "base/logging.h"
 #include "media/audio/shared_memory_util.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 
@@ skipping 11 matching lines @@
       shared_memory_size_(0),
 #if defined(OS_NACL)
       thread_id_(0),
       thread_active_(false),
 #endif
       callback_(NULL),
       user_data_(NULL) {
 }
 
 PPB_Audio_Shared::~PPB_Audio_Shared() {
+  // Shut down the socket to escape any hanging |Receive|s.
+  if (socket_.get())
+    socket_->Shutdown();
   StopThread();
 }
 
 void PPB_Audio_Shared::SetCallback(PPB_Audio_Callback callback,
                                    void* user_data) {
   callback_ = callback;
   user_data_ = user_data;
 }
 
 void PPB_Audio_Shared::SetStartPlaybackState() {
@@ skipping 56 matching lines @@
       NULL == thread_functions.thread_join)
     return;
 
   int result = thread_functions.thread_create(&thread_id_, CallRun, this);
   DCHECK_EQ(result, 0);
   thread_active_ = true;
 #endif
 }
 
 void PPB_Audio_Shared::StopThread() {
-  // Shut down the socket to escape any hanging |Receive|s.
-  if (socket_.get())
-    socket_->Shutdown();
-  #if !defined(OS_NACL)
+#if !defined(OS_NACL)
   if (audio_thread_.get()) {
     audio_thread_->Join();
     audio_thread_.reset();
   }
 #else
   if (thread_active_) {
     int result = thread_functions.thread_join(thread_id_);
     DCHECK_EQ(0, result);
     thread_active_ = false;
   }
@@ skipping 25 matching lines @@
       pending_data != media::kPauseMark) {
     callback_(buffer, shared_memory_size_, user_data_);
 
     // Let the host know we are done.
     media::SetActualDataSizeInBytes(
         shared_memory_.get(), shared_memory_size_, shared_memory_size_);
   }
 }
 
 }  // namespace ppapi