PPAPI: Make blocking completion callbacks work.

ppapi/shared_impl/ppb_audio_config_shared.cc

Index: ppapi/shared_impl/ppb_audio_config_shared.cc
diff --git a/ppapi/shared_impl/ppb_audio_config_shared.cc b/ppapi/shared_impl/ppb_audio_config_shared.cc
index 6803c3cf2fa52529c6fdeb23dc1e3fa302a47301..1252de730e7e4a2fb926022f3dcf4251f0ef1f46 100644
--- a/ppapi/shared_impl/ppb_audio_config_shared.cc
+++ b/ppapi/shared_impl/ppb_audio_config_shared.cc
@@ -50,7 +50,7 @@ uint32_t PPB_AudioConfig_Shared::RecommendSampleFrameCount_1_1(
     uint32_t sample_frame_count) {
   // Version 1.1: Query the back-end hardware for sample rate and buffer size,
   // and recommend a best fit based on request.
-  thunk::EnterInstance enter(instance);
+  thunk::EnterInstanceNoLock enter(instance);
   if (enter.failed())
     return 0;
 
@@ -92,7 +92,7 @@ uint32_t PPB_AudioConfig_Shared::RecommendSampleFrameCount_1_1(
 // static
 PP_AudioSampleRate PPB_AudioConfig_Shared::RecommendSampleRate(
     PP_Instance instance) {
-  thunk::EnterInstance enter(instance);
+  thunk::EnterInstanceNoLock enter(instance);
   if (enter.failed())
     return PP_AUDIOSAMPLERATE_NONE;
   PP_AudioSampleRate hardware_sample_rate = static_cast<PP_AudioSampleRate>(