Modifies AudioInputCallback::OnData and use media::AudioBus instead of plain byte vector (Relanding)

content/browser/renderer_host/media/audio_input_sync_writer.cc

Index: content/browser/renderer_host/media/audio_input_sync_writer.cc
diff --git a/content/browser/renderer_host/media/audio_input_sync_writer.cc b/content/browser/renderer_host/media/audio_input_sync_writer.cc
index 99b91b7b9f6b8fcf2e19c2df0504f593c16b2d21..a043500a716a493514d14aa9c4ce2e80d0c935ca 100644
--- a/content/browser/renderer_host/media/audio_input_sync_writer.cc
+++ b/content/browser/renderer_host/media/audio_input_sync_writer.cc
@@ -9,19 +9,36 @@
 #include "base/memory/shared_memory.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 
+using media::AudioBus;
+
 namespace content {
 
-AudioInputSyncWriter::AudioInputSyncWriter(
-    base::SharedMemory* shared_memory,
-    int shared_memory_segment_count)
+AudioInputSyncWriter::AudioInputSyncWriter(base::SharedMemory* shared_memory,
+                                           int shared_memory_segment_count,
+                                           const media::AudioParameters& params)
     : shared_memory_(shared_memory),
       shared_memory_segment_count_(shared_memory_segment_count),
       current_segment_id_(0),
-      creation_time_(base::Time::Now()) {
+      creation_time_(base::Time::Now()),
+      audio_bus_memory_size_(AudioBus::CalculateMemorySize(params)) {
   DCHECK_GT(shared_memory_segment_count, 0);
   DCHECK_EQ(shared_memory->requested_size() % shared_memory_segment_count, 0u);
   shared_memory_segment_size_ =
       shared_memory->requested_size() / shared_memory_segment_count;
+  DVLOG(1) << "SharedMemory::requested_size: "
+           << shared_memory->requested_size();
+  DVLOG(1) << "shared_memory_segment_count: " << shared_memory_segment_count;
+
+  // Create vector of audio buses by wrapping existing blocks of memory.
+  uint8* ptr = static_cast<uint8*>(shared_memory_->memory());
+  for (int i = 0; i < shared_memory_segment_count; ++i) {
+    media::AudioInputBuffer* buffer =
+        reinterpret_cast<media::AudioInputBuffer*>(ptr);
+    scoped_ptr<media::AudioBus> audio_bus =
+        media::AudioBus::WrapMemory(params, buffer->audio);
+    audio_buses_.push_back(audio_bus.release());
+    ptr += shared_memory_segment_size_;
+  }
 }
 
 AudioInputSyncWriter::~AudioInputSyncWriter() {}
@@ -31,10 +48,9 @@ void AudioInputSyncWriter::UpdateRecordedBytes(uint32 bytes) {
   socket_->Send(&bytes, sizeof(bytes));
 }
 
-uint32 AudioInputSyncWriter::Write(const void* data,
-                                   uint32 size,
-                                   double volume,
-                                   bool key_pressed) {
+void AudioInputSyncWriter::Write(const media::AudioBus* data,
+                                 double volume,
+                                 bool key_pressed) {
 #if !defined(OS_ANDROID)
   static const base::TimeDelta kLogDelayThreadhold =
       base::TimeDelta::FromMilliseconds(500);
@@ -59,19 +75,22 @@ uint32 AudioInputSyncWriter::Write(const void* data,
   last_write_time_ = base::Time::Now();
 #endif
 
+  // Write audio parameters to shared memory.
   uint8* ptr = static_cast<uint8*>(shared_memory_->memory());
   ptr += current_segment_id_ * shared_memory_segment_size_;
   media::AudioInputBuffer* buffer =
       reinterpret_cast<media::AudioInputBuffer*>(ptr);
   buffer->params.volume = volume;
-  buffer->params.size = size;
+  buffer->params.size = audio_bus_memory_size_;
   buffer->params.key_pressed = key_pressed;
-  memcpy(buffer->audio, data, size);
+
+  // Copy data from the native audio layer into shared memory using pre-
+  // allocated audio buses.
+  media::AudioBus* audio_bus = audio_buses_[current_segment_id_];
+  data->CopyTo(audio_bus);
 
   if (++current_segment_id_ >= shared_memory_segment_count_)
     current_segment_id_ = 0;
-
-  return size;
 }
 
 void AudioInputSyncWriter::Close() {