Switch OnMoreData() to use AudioBus.

ppapi/shared_impl/ppb_audio_shared.cc

Index: ppapi/shared_impl/ppb_audio_shared.cc
diff --git a/ppapi/shared_impl/ppb_audio_shared.cc b/ppapi/shared_impl/ppb_audio_shared.cc
index 5cf30026cc7e2b84429bfe27bc445fdabacf0936..901fbc18dbe7f9f74e6bc03c8152895b08bbb73a 100644
--- a/ppapi/shared_impl/ppb_audio_shared.cc
+++ b/ppapi/shared_impl/ppb_audio_shared.cc
@@ -8,6 +8,10 @@
 #include "media/audio/shared_memory_util.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 
+// Hard coded values from PepperPlatformAudioOutputImpl.
+// TODO(???): PPAPI shouldn't hard code these values for all clients.
+enum { kChannels = 2, kBytesPerSample = 2 };
+
 namespace ppapi {
 
 #if defined(OS_NACL)
@@ -25,7 +29,8 @@ PPB_Audio_Shared::PPB_Audio_Shared()
       thread_active_(false),
 #endif
       callback_(NULL),
-      user_data_(NULL) {
+      user_data_(NULL),
+      audio_buffer_size_(0) {
 }
 
 PPB_Audio_Shared::~PPB_Audio_Shared() {
@@ -73,6 +78,15 @@ void PPB_Audio_Shared::SetStreamInfo(
           media::TotalSharedMemorySizeInBytes(shared_memory_size_))) {
     PpapiGlobals::Get()->LogWithSource(instance, PP_LOGLEVEL_WARNING, "",
       "Failed to map shared memory for PPB_Audio_Shared.");
+  } else {
+    // Deduce the frame count from the size using hard coded channel count.
+    audio_bus_ = media::AudioBus::WrapMemory(
+        kChannels, shared_memory_size_ / (sizeof(float) * kChannels),
+        shared_memory_.get());
+    // Setup integer audio buffer for user audio data.
+    audio_buffer_size_ =
+        audio_bus_->frames() * audio_bus_->channels() * kBytesPerSample;
+    audio_buffer_.reset(new uint8_t[audio_buffer_size_]);
   }
 
   StartThread();
@@ -80,12 +94,14 @@ void PPB_Audio_Shared::SetStreamInfo(
 
 void PPB_Audio_Shared::StartThread() {
   // Don't start the thread unless all our state is set up correctly.
-  if (!playing_ || !callback_ || !socket_.get() || !shared_memory_->memory())
+  if (!playing_ || !callback_ || !socket_.get() || !shared_memory_->memory() ||
+      !audio_bus_.get() || !audio_buffer_.get())
     return;
   // Clear contents of shm buffer before starting audio thread. This will
   // prevent a burst of static if for some reason the audio thread doesn't
   // start up quickly enough.
   memset(shared_memory_->memory(), 0, shared_memory_size_);
+  memset(audio_buffer_.get(), 0, audio_buffer_size_);
 #if !defined(OS_NACL)
   DCHECK(!audio_thread_.get());
   audio_thread_.reset(new base::DelegateSimpleThread(
@@ -140,12 +156,15 @@ void PPB_Audio_Shared::CallRun(void* self) {
 
 void PPB_Audio_Shared::Run() {
   int pending_data;
-  void* buffer = shared_memory_->memory();
 
   while (sizeof(pending_data) ==
       socket_->Receive(&pending_data, sizeof(pending_data)) &&
       pending_data != media::kPauseMark) {
-    callback_(buffer, shared_memory_size_, user_data_);
+    callback_(audio_buffer_.get(), audio_buffer_size_, user_data_);
+
+    // Deinterleave the audio data into the shared memory as float.
+    audio_bus_->FromInterleaved(
+        audio_buffer_.get(), audio_bus_->frames(), kBytesPerSample);
 
     // Let the host know we are done.
     media::SetActualDataSizeInBytes(