Part 1: Plumb render view ID to render host

content/renderer/pepper/pepper_platform_audio_output_impl.cc

Index: content/renderer/pepper/pepper_platform_audio_output_impl.cc
diff --git a/content/renderer/pepper/pepper_platform_audio_output_impl.cc b/content/renderer/pepper/pepper_platform_audio_output_impl.cc
index 5f1f57da338994d91222b73a0c9ed8ed62aee8bf..f9e258e9e2755a9411412e4d1b5fc536757c822c 100644
--- a/content/renderer/pepper/pepper_platform_audio_output_impl.cc
+++ b/content/renderer/pepper/pepper_platform_audio_output_impl.cc
@@ -12,17 +12,19 @@
 #include "content/common/media/audio_messages.h"
 #include "content/renderer/media/audio_hardware.h"
 #include "content/renderer/media/audio_message_filter.h"
+#include "content/renderer/media/audio_output_ipc.h"
 #include "content/renderer/render_thread_impl.h"
 
 namespace content {
 
 // static
 PepperPlatformAudioOutputImpl* PepperPlatformAudioOutputImpl::Create(
+    int render_view_id,
     int sample_rate,
     int frames_per_buffer,
     webkit::ppapi::PluginDelegate::PlatformAudioOutputClient* client) {
   scoped_refptr<PepperPlatformAudioOutputImpl> audio_output(
-      new PepperPlatformAudioOutputImpl());
+      new PepperPlatformAudioOutputImpl(render_view_id));
   if (audio_output->Initialize(sample_rate, frames_per_buffer, client)) {
     // Balanced by Release invoked in
     // PepperPlatformAudioOutputImpl::ShutDownOnIOThread().
@@ -32,7 +34,7 @@ PepperPlatformAudioOutputImpl* PepperPlatformAudioOutputImpl::Create(
 }
 
 bool PepperPlatformAudioOutputImpl::StartPlayback() {
-  if (ipc_) {
+  if (ipc_.get()) {
     ChildProcess::current()->io_message_loop()->PostTask(
         FROM_HERE,
         base::Bind(&PepperPlatformAudioOutputImpl::StartPlaybackOnIOThread,
@@ -43,7 +45,7 @@ bool PepperPlatformAudioOutputImpl::StartPlayback() {
 }
 
 bool PepperPlatformAudioOutputImpl::StopPlayback() {
-  if (ipc_) {
+  if (ipc_.get()) {
     ChildProcess::current()->io_message_loop()->PostTask(
         FROM_HERE,
         base::Bind(&PepperPlatformAudioOutputImpl::StopPlaybackOnIOThread,
@@ -92,7 +94,7 @@ void PepperPlatformAudioOutputImpl::OnStreamCreated(
 }
 
 void PepperPlatformAudioOutputImpl::OnIPCClosed() {
-  ipc_ = NULL;
+  ipc_.reset();
 }
 
 PepperPlatformAudioOutputImpl::~PepperPlatformAudioOutputImpl() {
@@ -102,11 +104,12 @@ PepperPlatformAudioOutputImpl::~PepperPlatformAudioOutputImpl() {
   DCHECK(!client_);
 }
 
-PepperPlatformAudioOutputImpl::PepperPlatformAudioOutputImpl()
+PepperPlatformAudioOutputImpl::PepperPlatformAudioOutputImpl(
+    int render_view_id)
     : client_(NULL),
       stream_id_(0),
       main_message_loop_proxy_(base::MessageLoopProxy::current()) {
-  ipc_ = RenderThreadImpl::current()->audio_message_filter();
+  ipc_.reset(new AudioOutputIPC(render_view_id));
 }
 
 bool PepperPlatformAudioOutputImpl::Initialize(