PPAPI/NaCl: Move handle extraction code to ppapi/proxy

ppapi/proxy/handle_converter.cc

Index: ppapi/proxy/handle_converter.cc
diff --git a/chrome/nacl/nacl_ipc_adapter.cc b/ppapi/proxy/handle_converter.cc
similarity index 23%
copy from chrome/nacl/nacl_ipc_adapter.cc
copy to ppapi/proxy/handle_converter.cc
index a50c714891433fea6708a20704dffa0b1d015d04..a6690628bbee4d590b9f6a044bd6d28f5a96b3f5 100644
--- a/chrome/nacl/nacl_ipc_adapter.cc
+++ b/ppapi/proxy/handle_converter.cc
@@ -1,98 +1,21 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/nacl/nacl_ipc_adapter.h"
+#include "ppapi/proxy/handle_converter.h"
 
-#include <limits.h>
-#include <string.h>
-
-#include "base/basictypes.h"
-#include "base/bind.h"
-#include "base/location.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/shared_memory.h"
-#include "build/build_config.h"
-#include "ipc/ipc_channel.h"
+#include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
-#include "ipc/ipc_platform_file.h"
-#include "native_client/src/trusted/desc/nacl_desc_custom.h"
-#include "native_client/src/trusted/desc/nacl_desc_wrapper.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_message_params.h"
+#include "ppapi/proxy/serialized_handle.h"
 
-namespace {
-
-enum BufferSizeStatus {
-  // The buffer contains a full message with no extra bytes.
-  MESSAGE_IS_COMPLETE,
-
-  // The message doesn't fit and the buffer contains only some of it.
-  MESSAGE_IS_TRUNCATED,
-
-  // The buffer contains a full message + extra data.
-  MESSAGE_HAS_EXTRA_DATA
-};
-
-BufferSizeStatus GetBufferStatus(const char* data, size_t len) {
-  if (len < sizeof(NaClIPCAdapter::NaClMessageHeader))
-    return MESSAGE_IS_TRUNCATED;
-
-  const NaClIPCAdapter::NaClMessageHeader* header =
-      reinterpret_cast<const NaClIPCAdapter::NaClMessageHeader*>(data);
-  uint32 message_size =
-      sizeof(NaClIPCAdapter::NaClMessageHeader) + header->payload_size;
-
-  if (len == message_size)
-    return MESSAGE_IS_COMPLETE;
-  if (len > message_size)
-    return MESSAGE_HAS_EXTRA_DATA;
-  return MESSAGE_IS_TRUNCATED;
-}
-
-// This object allows the NaClDesc to hold a reference to a NaClIPCAdapter and
-// forward calls to it.
-struct DescThunker {
-  explicit DescThunker(NaClIPCAdapter* adapter_param)
-      : adapter(adapter_param) {
-  }
-  scoped_refptr<NaClIPCAdapter> adapter;
-};
-
-NaClIPCAdapter* ToAdapter(void* handle) {
-  return static_cast<DescThunker*>(handle)->adapter.get();
-}
-
-// NaClDescCustom implementation.
-void NaClDescCustomDestroy(void* handle) {
-  delete static_cast<DescThunker*>(handle);
-}
-
-ssize_t NaClDescCustomSendMsg(void* handle, const NaClImcTypedMsgHdr* msg,
-                              int /* flags */) {
-  return static_cast<ssize_t>(ToAdapter(handle)->Send(msg));
-}
-
-ssize_t NaClDescCustomRecvMsg(void* handle, NaClImcTypedMsgHdr* msg,
-                              int /* flags */) {
-  return static_cast<ssize_t>(ToAdapter(handle)->BlockingReceive(msg));
-}
-
-NaClDesc* MakeNaClDescCustom(NaClIPCAdapter* adapter) {
-  NaClDescCustomFuncs funcs = NACL_DESC_CUSTOM_FUNCS_INITIALIZER;
-  funcs.Destroy = NaClDescCustomDestroy;
-  funcs.SendMsg = NaClDescCustomSendMsg;
-  funcs.RecvMsg = NaClDescCustomRecvMsg;
-  // NaClDescMakeCustomDesc gives us a reference on the returned NaClDesc.
-  return NaClDescMakeCustomDesc(new DescThunker(adapter), &funcs);
+namespace IPC {
+class Message;
 }
 
-void DeleteChannel(IPC::Channel* channel) {
-  delete channel;
-}
+namespace {
 
-// TODO(dmichael): Move all this handle conversion code to ppapi/proxy.
-//                 crbug.com/165201
 void WriteHandle(int handle_index,
                  const ppapi::proxy::SerializedHandle& handle,
                  IPC::Message* message) {
@@ -196,9 +119,9 @@ void ConvertHandlesImpl(const Tuple4<A, B, C, D>& t1, Handles* handles,
 }
 
 template <class MessageType>
-class HandleConverter {
+class HandleConverterImpl {
  public:
-  explicit HandleConverter(const IPC::Message* msg)
+  explicit HandleConverterImpl(const IPC::Message* msg)
       : msg_(static_cast<const MessageType*>(msg)) {
   }
   bool ConvertMessage(Handles* handles, IPC::Message* out_msg) {
@@ -233,499 +156,103 @@ class HandleConverter {
 
 }  // namespace
 
-class NaClIPCAdapter::RewrittenMessage
-    : public base::RefCounted<RewrittenMessage> {
- public:
-  RewrittenMessage();
-
-  bool is_consumed() const { return data_read_cursor_ == data_len_; }
-
-  void SetData(const NaClIPCAdapter::NaClMessageHeader& header,
-               const void* payload, size_t payload_length);
-
-  int Read(NaClImcTypedMsgHdr* msg);
-
-  void AddDescriptor(nacl::DescWrapper* desc) { descs_.push_back(desc); }
-
-  size_t desc_count() const { return descs_.size(); }
-
- private:
-  friend class base::RefCounted<RewrittenMessage>;
-  ~RewrittenMessage() {}
-
-  scoped_array<char> data_;
-  size_t data_len_;
-
-  // Offset into data where the next read will happen. This will be equal to
-  // data_len_ when all data has been consumed.
-  size_t data_read_cursor_;
-
-  // Wrapped descriptors for transfer to untrusted code.
-  ScopedVector<nacl::DescWrapper> descs_;
-};
-
-NaClIPCAdapter::RewrittenMessage::RewrittenMessage()
-    : data_len_(0),
-      data_read_cursor_(0) {
-}
-
-void NaClIPCAdapter::RewrittenMessage::SetData(
-    const NaClIPCAdapter::NaClMessageHeader& header,
-    const void* payload,
-    size_t payload_length) {
-  DCHECK(!data_.get() && data_len_ == 0);
-  size_t header_len = sizeof(NaClIPCAdapter::NaClMessageHeader);
-  data_len_ = header_len + payload_length;
-  data_.reset(new char[data_len_]);
-
-  memcpy(data_.get(), &header, sizeof(NaClIPCAdapter::NaClMessageHeader));
-  memcpy(&data_[header_len], payload, payload_length);
-}
-
-int NaClIPCAdapter::RewrittenMessage::Read(NaClImcTypedMsgHdr* msg) {
-  CHECK(data_len_ >= data_read_cursor_);
-  char* dest_buffer = static_cast<char*>(msg->iov[0].base);
-  size_t dest_buffer_size = msg->iov[0].length;
-  size_t bytes_to_write = std::min(dest_buffer_size,
-                                   data_len_ - data_read_cursor_);
-  if (bytes_to_write == 0)
-    return 0;
-
-  memcpy(dest_buffer, &data_[data_read_cursor_], bytes_to_write);
-  data_read_cursor_ += bytes_to_write;
-
-  // Once all data has been consumed, transfer any file descriptors.
-  if (is_consumed()) {
-    nacl_abi_size_t desc_count = static_cast<nacl_abi_size_t>(descs_.size());
-    CHECK(desc_count <= msg->ndesc_length);
-    msg->ndesc_length = desc_count;
-    for (nacl_abi_size_t i = 0; i < desc_count; i++) {
-      // Copy the NaClDesc to the buffer and add a ref so it won't be freed
-      // when we clear our ScopedVector.
-      msg->ndescv[i] = descs_[i]->desc();
-      NaClDescRef(descs_[i]->desc());
-    }
-    descs_.clear();
-  } else {
-    msg->ndesc_length = 0;
-  }
-  return static_cast<int>(bytes_to_write);
-}
-
-NaClIPCAdapter::LockedData::LockedData()
-    : channel_closed_(false) {
-}
-
-NaClIPCAdapter::LockedData::~LockedData() {
-}
-
-NaClIPCAdapter::IOThreadData::IOThreadData() {
-}
-
-NaClIPCAdapter::IOThreadData::~IOThreadData() {
-}
-
-NaClIPCAdapter::NaClIPCAdapter(const IPC::ChannelHandle& handle,
-                               base::TaskRunner* runner)
-    : lock_(),
-      cond_var_(&lock_),
-      task_runner_(runner),
-      locked_data_() {
-  io_thread_data_.channel_.reset(
-      new IPC::Channel(handle, IPC::Channel::MODE_SERVER, this));
-  // Note, we can not PostTask for ConnectChannelOnIOThread here. If we did,
-  // and that task ran before this constructor completes, the reference count
-  // would go to 1 and then to 0 because of the Task, before we've been returned
-  // to the owning scoped_refptr, which is supposed to give us our first
-  // ref-count.
-}
-
-NaClIPCAdapter::NaClIPCAdapter(scoped_ptr<IPC::Channel> channel,
-                               base::TaskRunner* runner)
-    : lock_(),
-      cond_var_(&lock_),
-      task_runner_(runner),
-      locked_data_() {
-  io_thread_data_.channel_ = channel.Pass();
-}
-
-void NaClIPCAdapter::ConnectChannel() {
-  task_runner_->PostTask(FROM_HERE,
-      base::Bind(&NaClIPCAdapter::ConnectChannelOnIOThread, this));
-}
-
-// Note that this message is controlled by the untrusted code. So we should be
-// skeptical of anything it contains and quick to give up if anything is fishy.
-int NaClIPCAdapter::Send(const NaClImcTypedMsgHdr* msg) {
-  if (msg->iov_length != 1)
-    return -1;
-
-  base::AutoLock lock(lock_);
-
-  const char* input_data = static_cast<char*>(msg->iov[0].base);
-  size_t input_data_len = msg->iov[0].length;
-  if (input_data_len > IPC::Channel::kMaximumMessageSize) {
-    ClearToBeSent();
-    return -1;
-  }
-
-  // current_message[_len] refers to the total input data received so far.
-  const char* current_message;
-  size_t current_message_len;
-  bool did_append_input_data;
-  if (locked_data_.to_be_sent_.empty()) {
-    // No accumulated data, we can avoid a copy by referring to the input
-    // buffer (the entire message fitting in one call is the common case).
-    current_message = input_data;
-    current_message_len = input_data_len;
-    did_append_input_data = false;
-  } else {
-    // We've already accumulated some data, accumulate this new data and
-    // point to the beginning of the buffer.
-
-    // Make sure our accumulated message size doesn't overflow our max. Since
-    // we know that data_len < max size (checked above) and our current
-    // accumulated value is also < max size, we just need to make sure that
-    // 2x max size can never overflow.
-    COMPILE_ASSERT(IPC::Channel::kMaximumMessageSize < (UINT_MAX / 2),
-                   MaximumMessageSizeWillOverflow);
-    size_t new_size = locked_data_.to_be_sent_.size() + input_data_len;
-    if (new_size > IPC::Channel::kMaximumMessageSize) {
-      ClearToBeSent();
-      return -1;
-    }
-
-    locked_data_.to_be_sent_.append(input_data, input_data_len);
-    current_message = &locked_data_.to_be_sent_[0];
-    current_message_len = locked_data_.to_be_sent_.size();
-    did_append_input_data = true;
-  }
-
-  // Check the total data we've accumulated so far to see if it contains a full
-  // message.
-  switch (GetBufferStatus(current_message, current_message_len)) {
-    case MESSAGE_IS_COMPLETE: {
-      // Got a complete message, can send it out. This will be the common case.
-      bool success = SendCompleteMessage(current_message, current_message_len);
-      ClearToBeSent();
-      return success ? static_cast<int>(input_data_len) : -1;
-    }
-    case MESSAGE_IS_TRUNCATED:
-      // For truncated messages, just accumulate the new data (if we didn't
-      // already do so above) and go back to waiting for more.
-      if (!did_append_input_data)
-        locked_data_.to_be_sent_.append(input_data, input_data_len);
-      return static_cast<int>(input_data_len);
-    case MESSAGE_HAS_EXTRA_DATA:
-    default:
-      // When the plugin gives us too much data, it's an error.
-      ClearToBeSent();
-      return -1;
-  }
-}
-
-int NaClIPCAdapter::BlockingReceive(NaClImcTypedMsgHdr* msg) {
-  if (msg->iov_length != 1)
-    return -1;
-
-  int retval = 0;
-  {
-    base::AutoLock lock(lock_);
-    while (locked_data_.to_be_received_.empty() &&
-           !locked_data_.channel_closed_)
-      cond_var_.Wait();
-    if (locked_data_.channel_closed_) {
-      retval = -1;
-    } else {
-      retval = LockedReceive(msg);
-      DCHECK(retval > 0);
-    }
-  }
-  cond_var_.Signal();
-  return retval;
-}
-
-void NaClIPCAdapter::CloseChannel() {
-  {
-    base::AutoLock lock(lock_);
-    locked_data_.channel_closed_ = true;
-  }
-  cond_var_.Signal();
-
-  task_runner_->PostTask(FROM_HERE,
-      base::Bind(&NaClIPCAdapter::CloseChannelOnIOThread, this));
-}
-
-NaClDesc* NaClIPCAdapter::MakeNaClDesc() {
-  return MakeNaClDescCustom(this);
-}
-
-#if defined(OS_POSIX)
-int NaClIPCAdapter::TakeClientFileDescriptor() {
-  return io_thread_data_.channel_->TakeClientFileDescriptor();
-}
-#endif
-
 #define CASE_FOR_MESSAGE(MESSAGE_TYPE) \
       case MESSAGE_TYPE::ID: { \
-        HandleConverter<MESSAGE_TYPE> extractor(&msg); \
-        if (!extractor.ConvertMessage(&handles, new_msg_ptr)) \
+        HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
+        if (!extractor.ConvertMessage(handles, new_msg_ptr->get())) \
           return false; \
         break; \
       }
 #define CASE_FOR_REPLY(MESSAGE_TYPE) \
       case MESSAGE_TYPE::ID: { \
-        HandleConverter<MESSAGE_TYPE> extractor(&msg); \
+        HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
         if (!extractor.ConvertReply( \
-                &handles, \
-                static_cast<IPC::SyncMessage*>(new_msg_ptr))) \
+                handles, \
+                static_cast<IPC::SyncMessage*>(new_msg_ptr->get()))) \
           return false; \
         break; \
       }
 
-bool NaClIPCAdapter::OnMessageReceived(const IPC::Message& msg) {
-  {
-    base::AutoLock lock(lock_);
-
-    scoped_refptr<RewrittenMessage> rewritten_msg(new RewrittenMessage);
-
-    // Pointer to the "new" message we will rewrite on Windows. On posix, this
-    // isn't necessary, so it will stay NULL.
-    IPC::Message* new_msg_ptr = NULL;
-    IPC::Message new_msg(msg.routing_id(), msg.type(), msg.priority());
+namespace ppapi {
+namespace proxy {
+
+class SerializedHandle;
+
+HandleConverter::HandleConverter() {
+}
+
+bool HandleConverter::ConvertNativeHandlesToPosix(
+    const IPC::Message& msg,
+    std::vector<SerializedHandle>* handles,
+    scoped_ptr<IPC::Message>* new_msg_ptr) {
+  DCHECK(handles);
+  DCHECK(new_msg_ptr);
+  DCHECK(!new_msg_ptr->get());
+
+  // In Windows, we need to re-write the contents of the message. This is
+  // because in Windows IPC code, native HANDLE values are serialized in the
+  // body of the message.
+  //
+  // In POSIX, we only serialize an index in to a FileDescriptorSet, and the
+  // actual file descriptors are sent out-of-band. So on Windows, to make a
+  // message that's compatible with Windows, we need to write a new message that
+  // has simple indices in the message body instead of the HANDLEs.
+  //
+  // NOTE: This means on Windows, new_msg_ptr's serialized contents are not
+  // compatible with Windows IPC deserialization code; it is intended to be
+  // passed to NaCl.
 #if defined(OS_WIN)
-    new_msg_ptr = &new_msg;
+  new_msg_ptr->reset(
+      new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
 #else
-    // Even on POSIX, we have to rewrite messages to create channels, because
-    // these contain a handle with an invalid (place holder) descriptor. The
-    // message sending code sees this and doesn't pass the descriptor over
-    // correctly.
-    if (msg.type() == PpapiMsg_CreateNaClChannel::ID)
-      new_msg_ptr = &new_msg;
+  // Even on POSIX, we have to rewrite messages to create channels, because
+  // these contain a handle with an invalid (place holder) descriptor. The
+  // message sending code sees this and doesn't pass the descriptor over
+  // correctly.
+  if (msg.type() == PpapiMsg_CreateNaClChannel::ID) {
+    new_msg_ptr->reset(
+        new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
+  }
 #endif
 
-    Handles handles;
-    switch (msg.type()) {
-      CASE_FOR_MESSAGE(PpapiMsg_CreateNaClChannel)
-      CASE_FOR_MESSAGE(PpapiMsg_PPBAudio_NotifyAudioStreamCreated)
-      CASE_FOR_MESSAGE(PpapiPluginMsg_ResourceReply)
-      case IPC_REPLY_ID: {
-        int id = IPC::SyncMessage::GetMessageId(msg);
-        LockedData::PendingSyncMsgMap::iterator iter(
-            locked_data_.pending_sync_msgs_.find(id));
-        if (iter == locked_data_.pending_sync_msgs_.end()) {
-          NOTREACHED();
-          return false;
-        }
-        uint32_t type = iter->second;
-        locked_data_.pending_sync_msgs_.erase(iter);
-        switch (type) {
-          CASE_FOR_REPLY(PpapiHostMsg_PPBGraphics3D_GetTransferBuffer)
-          CASE_FOR_REPLY(PpapiHostMsg_PPBImageData_CreateNaCl)
-          CASE_FOR_REPLY(PpapiHostMsg_ResourceSyncCall)
-          default:
-            // Do nothing for messages we don't know.
-            break;
-        }
-        break;
+  switch (msg.type()) {
+    CASE_FOR_MESSAGE(PpapiMsg_CreateNaClChannel)
+    CASE_FOR_MESSAGE(PpapiMsg_PPBAudio_NotifyAudioStreamCreated)
+    CASE_FOR_MESSAGE(PpapiPluginMsg_ResourceReply)
+    case IPC_REPLY_ID: {
+      int id = IPC::SyncMessage::GetMessageId(msg);
+      PendingSyncMsgMap::iterator iter(pending_sync_msgs_.find(id));
+      if (iter == pending_sync_msgs_.end()) {
+        NOTREACHED();
+        return false;
       }
-      default:
-        // Do nothing for messages we don't know.
-        break;
-    }
-    // Now add any descriptors we found to rewritten_msg. |handles| is usually
-    // empty, unless we read a message containing a FD or handle.
-    nacl::DescWrapperFactory factory;
-    for (Handles::const_iterator iter = handles.begin();
-         iter != handles.end();
-         ++iter) {
-      scoped_ptr<nacl::DescWrapper> nacl_desc;
-      switch (iter->type()) {
-        case ppapi::proxy::SerializedHandle::SHARED_MEMORY: {
-          const base::SharedMemoryHandle& shm_handle = iter->shmem();
-          uint32_t size = iter->size();
-          nacl_desc.reset(factory.ImportShmHandle(
-#if defined(OS_WIN)
-              reinterpret_cast<const NaClHandle>(shm_handle),
-#else
-              shm_handle.fd,
-#endif
-              static_cast<size_t>(size)));
-          break;
-        }
-        case ppapi::proxy::SerializedHandle::SOCKET: {
-          nacl_desc.reset(factory.ImportSyncSocketHandle(
-#if defined(OS_WIN)
-              reinterpret_cast<const NaClHandle>(iter->descriptor())
-#else
-              iter->descriptor().fd
-#endif
-          ));
-          break;
-        }
-        case ppapi::proxy::SerializedHandle::CHANNEL_HANDLE: {
-          // Check that this came from a PpapiMsg_CreateNaClChannel message.
-          // This code here is only appropriate for that message.
-          DCHECK(msg.type() == PpapiMsg_CreateNaClChannel::ID);
-          IPC::ChannelHandle channel_handle =
-              IPC::Channel::GenerateVerifiedChannelID("nacl");
-          scoped_refptr<NaClIPCAdapter> ipc_adapter(
-              new NaClIPCAdapter(channel_handle, task_runner_));
-          ipc_adapter->ConnectChannel();
-#if defined(OS_POSIX)
-          channel_handle.socket = base::FileDescriptor(
-              ipc_adapter->TakeClientFileDescriptor(), true);
-#endif
-          nacl_desc.reset(factory.MakeGeneric(ipc_adapter->MakeNaClDesc()));
-          // Send back a message that the channel was created.
-          scoped_ptr<IPC::Message> response(
-              new PpapiHostMsg_ChannelCreated(channel_handle));
-          task_runner_->PostTask(FROM_HERE,
-              base::Bind(&NaClIPCAdapter::SendMessageOnIOThread, this,
-                         base::Passed(&response)));
-          break;
-        }
-        case ppapi::proxy::SerializedHandle::FILE:
-          // TODO(raymes): Handle file handles for NaCl.
-          NOTIMPLEMENTED();
-          break;
-        case ppapi::proxy::SerializedHandle::INVALID: {
-          // Nothing to do. TODO(dmichael): Should we log this? Or is it
-          // sometimes okay to pass an INVALID handle?
+      uint32_t type = iter->second;
+      pending_sync_msgs_.erase(iter);
+      switch (type) {
+        CASE_FOR_REPLY(PpapiHostMsg_PPBGraphics3D_GetTransferBuffer)
+        CASE_FOR_REPLY(PpapiHostMsg_PPBImageData_CreateNaCl)
+        CASE_FOR_REPLY(PpapiHostMsg_ResourceSyncCall)
+        default:
+          // Do nothing for messages we don't know.
           break;
-        }
-        // No default, so the compiler will warn us if new types get added.
       }
-      if (nacl_desc.get())
-        rewritten_msg->AddDescriptor(nacl_desc.release());
+      break;
     }
-    if (new_msg_ptr && !handles.empty())
-      SaveMessage(*new_msg_ptr, rewritten_msg.get());
-    else
-      SaveMessage(msg, rewritten_msg.get());
-  }
-  cond_var_.Signal();
-  return true;
-}
-
-void NaClIPCAdapter::OnChannelConnected(int32 peer_pid) {
-}
-
-void NaClIPCAdapter::OnChannelError() {
-  CloseChannel();
-}
-
-NaClIPCAdapter::~NaClIPCAdapter() {
-  // Make sure the channel is deleted on the IO thread.
-  task_runner_->PostTask(FROM_HERE,
-      base::Bind(&DeleteChannel, io_thread_data_.channel_.release()));
-}
-
-int NaClIPCAdapter::LockedReceive(NaClImcTypedMsgHdr* msg) {
-  lock_.AssertAcquired();
-
-  if (locked_data_.to_be_received_.empty())
-    return 0;
-  scoped_refptr<RewrittenMessage> current =
-      locked_data_.to_be_received_.front();
-
-  int retval = current->Read(msg);
-
-  // When a message is entirely consumed, remove if from the waiting queue.
-  if (current->is_consumed())
-    locked_data_.to_be_received_.pop();
-
-  return retval;
-}
-
-bool NaClIPCAdapter::SendCompleteMessage(const char* buffer,
-                                         size_t buffer_len) {
-  // The message will have already been validated, so we know it's large enough
-  // for our header.
-  const NaClMessageHeader* header =
-      reinterpret_cast<const NaClMessageHeader*>(buffer);
-
-  // Length of the message not including the body. The data passed to us by the
-  // plugin should match that in the message header. This should have already
-  // been validated by GetBufferStatus.
-  int body_len = static_cast<int>(buffer_len - sizeof(NaClMessageHeader));
-  DCHECK(body_len == static_cast<int>(header->payload_size));
-
-  // We actually discard the flags and only copy the ones we care about. This
-  // is just because message doesn't have a constructor that takes raw flags.
-  scoped_ptr<IPC::Message> msg(
-      new IPC::Message(header->routing, header->type,
-                       IPC::Message::PRIORITY_NORMAL));
-  if (header->flags & IPC::Message::SYNC_BIT)
-    msg->set_sync();
-  if (header->flags & IPC::Message::REPLY_BIT)
-    msg->set_reply();
-  if (header->flags & IPC::Message::REPLY_ERROR_BIT)
-    msg->set_reply_error();
-  if (header->flags & IPC::Message::UNBLOCK_BIT)
-    msg->set_unblock(true);
-
-  msg->WriteBytes(&buffer[sizeof(NaClMessageHeader)], body_len);
-
-  // Technically we didn't have to do any of the previous work in the lock. But
-  // sometimes our buffer will point to the to_be_sent_ string which is
-  // protected by the lock, and it's messier to factor Send() such that it can
-  // unlock for us. Holding the lock for the message construction, which is
-  // just some memcpys, shouldn't be a big deal.
-  lock_.AssertAcquired();
-  if (locked_data_.channel_closed_)
-    return false;  // TODO(brettw) clean up handles here when we add support!
-
-  // Store the type of all sync messages so that later we can translate the
-  // reply if necessary.
-  if (msg->is_sync()) {
-    int id = IPC::SyncMessage::GetMessageId(*msg);
-    locked_data_.pending_sync_msgs_[id] = msg->type();
+    default:
+      // Do nothing for messages we don't know.
+      break;
   }
-  // Actual send must be done on the I/O thread.
-  task_runner_->PostTask(FROM_HERE,
-      base::Bind(&NaClIPCAdapter::SendMessageOnIOThread, this,
-                 base::Passed(&msg)));
   return true;
 }
 
-void NaClIPCAdapter::ClearToBeSent() {
-  lock_.AssertAcquired();
-
-  // Don't let the string keep its buffer behind our back.
-  std::string empty;
-  locked_data_.to_be_sent_.swap(empty);
-}
-
-void NaClIPCAdapter::ConnectChannelOnIOThread() {
-  if (!io_thread_data_.channel_->Connect())
-    NOTREACHED();
-}
-
-void NaClIPCAdapter::CloseChannelOnIOThread() {
-  io_thread_data_.channel_->Close();
-}
-
-void NaClIPCAdapter::SendMessageOnIOThread(scoped_ptr<IPC::Message> message) {
-  io_thread_data_.channel_->Send(message.release());
-}
-
-void NaClIPCAdapter::SaveMessage(const IPC::Message& msg,
-                                 RewrittenMessage* rewritten_msg) {
-  lock_.AssertAcquired();
-  // There is some padding in this structure (the "padding" member is 16
-  // bits but this then gets padded to 32 bits). We want to be sure not to
-  // leak data to the untrusted plugin, so zero everything out first.
-  NaClMessageHeader header;
-  memset(&header, 0, sizeof(NaClMessageHeader));
+void HandleConverter::RegisterSyncMessageForReply(const IPC::Message& msg) {
+  DCHECK(msg.is_sync());
 
-  header.payload_size = static_cast<uint32>(msg.payload_size());
-  header.routing = msg.routing_id();
-  header.type = msg.type();
-  header.flags = msg.flags();
-  header.num_fds = static_cast<int>(rewritten_msg->desc_count());
+  int msg_id = IPC::SyncMessage::GetMessageId(msg);
+  DCHECK(pending_sync_msgs_.find(msg_id) == pending_sync_msgs_.end());
 
-  rewritten_msg->SetData(header, msg.payload(), msg.payload_size());
-  locked_data_.to_be_received_.push(rewritten_msg);
+  pending_sync_msgs_[msg_id] = msg.type();
 }
 
+}  // namespace proxy
+}  // namespace ppapi