Use multiple shared memory buffers cyclically for audio capture.

content/renderer/pepper/pepper_platform_audio_input_impl.cc

Index: content/renderer/pepper/pepper_platform_audio_input_impl.cc
===================================================================
--- content/renderer/pepper/pepper_platform_audio_input_impl.cc	(revision 185810)
+++ content/renderer/pepper/pepper_platform_audio_input_impl.cc	(working copy)
@@ -64,17 +64,10 @@
 }
 
 void PepperPlatformAudioInputImpl::OnStreamCreated(
-    base::SharedMemoryHandle handle,
     base::SyncSocket::Handle socket_handle,
-    int length) {
-#if defined(OS_WIN)
-  DCHECK(handle);
-  DCHECK(socket_handle);
-#else
-  DCHECK_NE(-1, handle.fd);
-  DCHECK_NE(-1, socket_handle);
-#endif
-  DCHECK(length);
+    int total_handles) {
+  DCHECK_NE(socket_handle, base::SyncSocket::kInvalidHandle);
+  DCHECK_EQ(total_handles, 1);
 
   if (base::MessageLoopProxy::current() != main_message_loop_proxy_) {
     // No need to check |shutdown_called_| here. If shutdown has occurred,
@@ -83,15 +76,42 @@
     main_message_loop_proxy_->PostTask(
         FROM_HERE,
         base::Bind(&PepperPlatformAudioInputImpl::OnStreamCreated, this,
-                   handle, socket_handle, length));
+                   socket_handle, total_handles));
   } else {
     // Must dereference the client only on the main thread. Shutdown may have
     // occurred while the request was in-flight, so we need to NULL check.
     if (client_) {
-      client_->StreamCreated(handle, length, socket_handle);
+      socket_handle_ = socket_handle;
     } else {
       // Clean up the handles.
       base::SyncSocket temp_socket(socket_handle);
+    }
+  }
+}
+
+void PepperPlatformAudioInputImpl::OnSharedMemoryCreated(
+    base::SharedMemoryHandle handle,
+    int length,
+    int index) {
+  DCHECK(base::SharedMemory::IsHandleValid(handle));
+  DCHECK(length);
+  DCHECK_NE(socket_handle_, base::SyncSocket::kInvalidHandle);
+
+  if (base::MessageLoopProxy::current() != main_message_loop_proxy_) {
+    // No need to check |shutdown_called_| here. If shutdown has occurred,
+    // |client_| will be NULL and the handles will be cleaned up on the main
+    // thread.
+    main_message_loop_proxy_->PostTask(
+        FROM_HERE,
+        base::Bind(&PepperPlatformAudioInputImpl::OnSharedMemoryCreated, this,
+                   handle, length, index));
+  } else {
+    // Must dereference the client only on the main thread. Shutdown may have
+    // occurred while the request was in-flight, so we need to NULL check.
+    if (client_) {
+      client_->StreamCreated(handle, length, socket_handle_);
+    } else {
+      // Clean up the handles.
       base::SharedMemory temp_shared_memory(handle, false);
     }
   }
@@ -117,7 +137,7 @@
                    this));
   } else {
     // We will be notified by OnStreamCreated().
-    ipc_->CreateStream(stream_id_, params_, device_id, false);
+    ipc_->CreateStream(stream_id_, params_, device_id, false, 1);
   }
 }
 
@@ -139,6 +159,7 @@
 
 PepperPlatformAudioInputImpl::PepperPlatformAudioInputImpl()
     : client_(NULL),
+      socket_handle_(base::SyncSocket::kInvalidHandle),
       stream_id_(0),
       render_view_id_(MSG_ROUTING_NONE),
       main_message_loop_proxy_(base::MessageLoopProxy::current()),
@@ -196,7 +217,7 @@
   if (!session_id) {
     // We will be notified by OnStreamCreated().
     ipc_->CreateStream(stream_id_, params_,
-        media::AudioManagerBase::kDefaultDeviceId, false);
+        media::AudioManagerBase::kDefaultDeviceId, false, 1);
   } else {
     // We will be notified by OnDeviceReady().
     ipc_->StartDevice(stream_id_, session_id);