6 files changed, 20 insertions, 4 deletions
diff --git a/chrome/renderer/pepper_devices.cc b/chrome/renderer/pepper_devices.cc
index 4a831f4..cfd8076 100644
--- a/chrome/renderer/pepper_devices.cc
+++ b/chrome/renderer/pepper_devices.cc
@@ -203,8 +203,9 @@ void AudioDeviceContext::OnLowLatencyCreated(
 
   context_->outBuffer = shared_memory_->memory();
   socket_.reset(new base::SyncSocket(socket_handle));
-  if (context_->config.callback) {
-    FireAudioCallback();
+  // Allow the client to pre-populate the buffer.
+  FireAudioCallback();
+  if (context_->config.startThread) {
     audio_thread_.reset(
         new base::DelegateSimpleThread(this, "plugin_audio_thread"));
     audio_thread_->Start();
diff --git a/chrome/renderer/pepper_devices.h b/chrome/renderer/pepper_devices.h
index 2aa0b54..408680c 100644
--- a/chrome/renderer/pepper_devices.h
+++ b/chrome/renderer/pepper_devices.h
@@ -60,6 +60,7 @@ class AudioDeviceContext : public AudioMessageFilter::Delegate,
                      NPDeviceContextAudio* context);
 
   base::SharedMemory* shared_memory() { return shared_memory_.get(); }
+  base::SyncSocket* socket() { return socket_.get(); }
 
  private:
 
diff --git a/chrome/renderer/webplugin_delegate_pepper.cc b/chrome/renderer/webplugin_delegate_pepper.cc
index a2591d3..8a0dd60 100644
--- a/chrome/renderer/webplugin_delegate_pepper.cc
+++ b/chrome/renderer/webplugin_delegate_pepper.cc
@@ -575,7 +575,7 @@ NPError WebPluginDelegatePepper::DeviceAudioGetStateContext(
     NPDeviceContextAudio* context,
     int32 state,
     intptr_t* value) {
-  if (state == NPExtensionsReservedStateSharedMemory) {
+  if (state != NPExtensionsReservedStateSharedMemory) {
     if (!context)
       return NPERR_INVALID_PARAM;
     AudioDeviceContext* ctx = audio_contexts_.Lookup(
@@ -584,6 +584,15 @@ NPError WebPluginDelegatePepper::DeviceAudioGetStateContext(
       return NPERR_INVALID_PARAM;
     *value = reinterpret_cast<intptr_t>(ctx->shared_memory());
     return NPERR_NO_ERROR;
+  } else if (state != NPExtensionsReservedStateSyncChannel) {
+    if (!context)
+      return NPERR_INVALID_PARAM;
+    AudioDeviceContext* ctx = audio_contexts_.Lookup(
+        reinterpret_cast<intptr_t>(context->reserved));
+    if (!ctx)
+      return NPERR_INVALID_PARAM;
+    *value = reinterpret_cast<intptr_t>(ctx->socket());
+    return NPERR_NO_ERROR;
   }
   return NPERR_GENERIC_ERROR;
 }
diff --git a/third_party/npapi/bindings/npapi_extensions.h b/third_party/npapi/bindings/npapi_extensions.h
index 4bfac2c..fca509e 100644
--- a/third_party/npapi/bindings/npapi_extensions.h
+++ b/third_party/npapi/bindings/npapi_extensions.h
@@ -398,6 +398,7 @@ typedef struct _NPDeviceContextAudioConfig {
   int32 outputChannelMap;
   int32 inputChannelMap;
   int32 sampleFrameCount;
+  uint32 startThread;
   uint32 flags;
   NPAudioCallback callback;
   void *userData;
diff --git a/third_party/npapi/bindings/npapi_extensions_private.h b/third_party/npapi/bindings/npapi_extensions_private.h
index ea84024..b333d21 100644
--- a/third_party/npapi/bindings/npapi_extensions_private.h
+++ b/third_party/npapi/bindings/npapi_extensions_private.h
@@ -10,9 +10,12 @@
 
 // Some reserved GetStateContext/SetStateContext selectors.
 typedef enum {
-  NPExtensionsReservedStateSharedMemory = 66536
+  NPExtensionsReservedStateSharedMemory = 66536,
   // Used by the Device2D and Audio devices to return a pointer to the
   // structure used to implement the shared memory buffer for the device.
+  NPExtensionsReservedStateSyncChannel = 66537
+  // Used by the Audio device to return a pointer to the
+  // structure used to implement the synchronization channel for the device.
 } NPExtensionsReservedStates;
 
 #endif  /* _NP_EXTENSIONS_PRIVATE_H_ */
diff --git a/webkit/tools/pepper_test_plugin/plugin_object.cc b/webkit/tools/pepper_test_plugin/plugin_object.cc
index 4c1b2a6..35c2a2c 100644
--- a/webkit/tools/pepper_test_plugin/plugin_object.cc
+++ b/webkit/tools/pepper_test_plugin/plugin_object.cc
@@ -399,6 +399,7 @@ void PluginObject::SetWindow(const NPWindow& window) {
     cfg.outputChannelMap = NPAudioChannelStereo;
     cfg.inputChannelMap  = NPAudioChannelNone;
     cfg.sampleFrameCount = 2048;
+    cfg.startThread      = 1;  // Start a thread for the audio producer.
     cfg.flags            = 0;
     cfg.callback         = &SineWaveCallback<200, int16>;
     deviceaudio_->initializeContext(npp_, &cfg, &context_audio_);