Change sync primitives ownership for audio rendering.

content/browser/renderer_host/media/audio_sync_reader.cc

Index: content/browser/renderer_host/media/audio_sync_reader.cc
diff --git a/content/browser/renderer_host/media/audio_sync_reader.cc b/content/browser/renderer_host/media/audio_sync_reader.cc
index 51914e1a6f245886e07f312995a09cc36bd8e9a1..e1b4f4d033787c415fbeef5d113659dbdc804d60 100644
--- a/content/browser/renderer_host/media/audio_sync_reader.cc
+++ b/content/browser/renderer_host/media/audio_sync_reader.cc
@@ -5,6 +5,8 @@
 #include "content/browser/renderer_host/media/audio_sync_reader.h"
 
 #include <algorithm>
+#include <string>
+#include <utility>
 
 #include "base/command_line.h"
 #include "base/format_macros.h"
@@ -40,11 +42,16 @@ void LogAudioGlitchResult(AudioGlitchResult result) {
 
 namespace content {
 
-AudioSyncReader::AudioSyncReader(base::SharedMemory* shared_memory,
-                                 const media::AudioParameters& params)
-    : shared_memory_(shared_memory),
+AudioSyncReader::AudioSyncReader(
+    const media::AudioParameters& params,
+    std::unique_ptr<base::SharedMemory> shared_memory,
+    std::unique_ptr<base::CancelableSyncSocket> socket,
+    std::unique_ptr<base::CancelableSyncSocket> foreign_socket)
+    : shared_memory_(std::move(shared_memory)),
       mute_audio_(base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kMuteAudio)),
+      socket_(std::move(socket)),
+      foreign_socket_(std::move(foreign_socket)),
       packet_size_(shared_memory_->requested_size()),
       renderer_callback_count_(0),
       renderer_missed_callback_count_(0),
@@ -107,6 +114,28 @@ AudioSyncReader::~AudioSyncReader() {
   DVLOG(1) << log_string;
 }
 
+// static
+std::unique_ptr<AudioSyncReader> AudioSyncReader::Create(
+    const media::AudioParameters& params) {
+  std::unique_ptr<base::SharedMemory> shared_memory(new base::SharedMemory());
+  std::unique_ptr<base::CancelableSyncSocket> socket(
+      new base::CancelableSyncSocket());
+  std::unique_ptr<base::CancelableSyncSocket> foreign_socket(
+      new base::CancelableSyncSocket());
+
+  size_t memory_size = sizeof(media::AudioOutputBufferParameters) +

[o1ka, 2016/09/16 10:51:59]

const

[Max Morin, 2016/09/16 12:46:15]

Done.

+                       AudioBus::CalculateMemorySize(params);

[o1ka, 2016/09/16 10:51:59]

Since this is the value to be sent over IPC in the end, we may probably want to
use CheckedNumeric here?
https://cs.chromium.org/chromium/src/base/numerics/safe_math.h?l=50

[Max Morin, 2016/09/16 12:46:15]

Yes. Thinking about it, I'm not sure there's anything stopping the renderer from
asking for a month-long audio buffer, but there is probably something in the IPC
system that checks this. I'll add a note to myself to also fix this for mojo.
Fixed.

+
+  if (!shared_memory->CreateAndMapAnonymous(memory_size) ||
+      !base::CancelableSyncSocket::CreatePair(socket.get(),
+                                              foreign_socket.get())) {
+    return {};
+  }
+  return std::unique_ptr<AudioSyncReader>(
+      new AudioSyncReader(params, std::move(shared_memory), std::move(socket),
+                          std::move(foreign_socket)));
+}
+
 // media::AudioOutputController::SyncReader implementations.
 void AudioSyncReader::UpdatePendingBytes(uint32_t bytes,
                                          uint32_t frames_skipped) {
@@ -152,19 +181,6 @@ void AudioSyncReader::Close() {
   socket_->Close();
 }
 
-bool AudioSyncReader::Init() {
-  socket_.reset(new base::CancelableSyncSocket());
-  foreign_socket_.reset(new base::CancelableSyncSocket());
-  return base::CancelableSyncSocket::CreatePair(socket_.get(),
-                                                foreign_socket_.get());
-}
-
-bool AudioSyncReader::PrepareForeignSocket(
-    base::ProcessHandle process_handle,
-    base::SyncSocket::TransitDescriptor* descriptor) {
-  return foreign_socket_->PrepareTransitDescriptor(process_handle, descriptor);
-}
-
 bool AudioSyncReader::WaitUntilDataIsReady() {
   TRACE_EVENT0("audio", "AudioSyncReader::WaitUntilDataIsReady");
   base::TimeDelta timeout = maximum_wait_time_;