Ppapi audio: don't terminate thread on all negative pending_data.

pending_data should be used exclusively for synchronisation purposes, and not
as an indication of the fill level of the playback buffer. Change condition
to only quit on kPauseMark.

BUG=chromium-os:26151
TEST=Stressed as described in bug and watched Lumpy survive negative numbers.
Review URL: https://chromiumcodereview.appspot.com/9958093

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@130808 0039d316-1c4b-4281-b951-d872f2087c98

ppapi/shared_impl/ppb_audio_shared.cc

@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -8,6 +8,8 @@
 
 namespace ppapi {
 
+const int PPB_Audio_Shared::kPauseMark = -1;
+
 PPB_Audio_Shared::PPB_Audio_Shared()
     : playing_(false),
       shared_memory_size_(0),
@@ -86,7 +88,7 @@ void PPB_Audio_Shared::Run() {
 
   while (sizeof(pending_data) ==
       socket_->Receive(&pending_data, sizeof(pending_data)) &&
-      pending_data >= 0) {
+      pending_data != kPauseMark) {
     callback_(buffer, shared_memory_size_, user_data_);
   }
 }

ppapi/shared_impl/ppb_audio_shared.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -25,6 +25,9 @@ class PPAPI_SHARED_EXPORT PPB_Audio_Shared
   PPB_Audio_Shared();
   virtual ~PPB_Audio_Shared();
 
+  // Keep in sync with media::AudioOutputController::kPauseMark.
+  static const int kPauseMark;
+
   bool playing() const { return playing_; }
 
   // Sets the callback information that the background thread will use. This

webkit/plugins/ppapi/DEPS

@@ -3,6 +3,7 @@ include_rules = [
   "+ppapi/shared_impl",
   "+ppapi/thunk",
   "+printing",
+  "+media/audio",
   "+media/video",
   "+ui/base/ime",
   "+ui/base/range",

webkit/plugins/ppapi/ppb_audio_impl.cc

@@ -5,6 +5,7 @@
 #include "webkit/plugins/ppapi/ppb_audio_impl.h"
 
 #include "base/logging.h"
+#include "media/audio/audio_output_controller.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/ppb_audio.h"
 #include "ppapi/c/ppb_audio_config.h"
@@ -52,6 +53,8 @@ PP_Resource PPB_Audio_Impl::Create(PP_Instance instance,
   scoped_refptr<PPB_Audio_Impl> audio(new PPB_Audio_Impl(instance));
   if (!audio->Init(config, audio_callback, user_data))
     return 0;
+  CHECK(media::AudioOutputController::kPauseMark ==
+      ::ppapi::PPB_Audio_Shared::kPauseMark);
   return audio->GetReference();
 }