WIP: A couple of more ChannelMojo speedup ideas

ipc/mojo/ipc_message_pipe_reader.cc

 // Copyright 2014 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 "ipc/mojo/ipc_message_pipe_reader.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
-#include "ipc/mojo/async_handle_waiter.h"
 #include "ipc/mojo/ipc_channel_mojo.h"
 
 namespace IPC {
 namespace internal {
 
 MessagePipeReader::MessagePipeReader(mojo::ScopedMessagePipeHandle handle,
                                      MessagePipeReader::Delegate* delegate)
     : pipe_(handle.Pass()),
       delegate_(delegate),
-      async_waiter_(
-          new AsyncHandleWaiter(base::Bind(&MessagePipeReader::PipeIsReady,
-                                           base::Unretained(this)))) {
+      async_waiter_(new AsyncHandleWaiter(this)) {
+  async_waiter_->SetMessageCallback(pipe_.get().value());
 }
 
 MessagePipeReader::~MessagePipeReader() {
   CHECK(!IsValid());
 }
 
 void MessagePipeReader::Close() {
+  if (async_waiter_)
+    async_waiter_->ClearMessageCallback(pipe_.get().value());
   async_waiter_.reset();
   pipe_.reset();
   OnPipeClosed();
 }
 
 void MessagePipeReader::CloseWithError(MojoResult error) {
   OnPipeError(error);
   Close();
 }
 
@@ skipping 146 matching lines @@
       OnPipeError(wait_result);
     }
 
     Close();
     return;
   }
 
   ReadMessagesThenWait();
 }
 
+void MessagePipeReader::MessageWasArrived(const void* bytes,
+                                          uint32_t num_bytes) {
+  Message message(reinterpret_cast<const char*>(bytes),
+                  static_cast<int>(num_bytes));
+  delegate_->OnMessageReceived(message);
+}
+
 void MessagePipeReader::DelayedDeleter::operator()(
     MessagePipeReader* ptr) const {
   ptr->Close();
   base::MessageLoopProxy::current()->PostTask(
       FROM_HERE, base::Bind(&DeleteNow, ptr));
 }
 
 }  // namespace internal
 }  // namespace IPC