Revert of Revert of IPC::ChannelMojo: Make IPC handling robust against bad messages.

ipc/mojo/ipc_mojo_bootstrap.h

 // 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.
 
 #ifndef IPC_MOJO_IPC_MOJO_BOOTSTRAP_H_
 #define IPC_MOJO_IPC_MOJO_BOOTSTRAP_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/process/process_handle.h"
 #include "ipc/ipc_channel.h"
@@ skipping 37 matching lines @@
 
   // Each client should call this once the process handle becomes known.
   virtual void OnClientLaunched(base::ProcessHandle process) = 0;
 
 #if defined(OS_POSIX) && !defined(OS_NACL)
   int GetClientFileDescriptor() const;
   base::ScopedFD TakeClientFileDescriptor();
 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 
  protected:
+  // On MojoServerBootstrap: INITIALIZED -> WAITING_ACK -> READY
+  // On MojoClientBootstrap: INITIALIZED -> READY
+  // STATE_ERROR is a catch-all state that captures any observed error.
   enum State { STATE_INITIALIZED, STATE_WAITING_ACK, STATE_READY, STATE_ERROR };
 
   Delegate* delegate() const { return delegate_; }
   bool Send(Message* message);
   void Fail();
   bool HasFailed() const;
 
   State state() const { return state_; }
   void set_state(State state) { state_ = state; }
 
  private:
   void Init(scoped_ptr<Channel> channel, Delegate* delegate);
 
   // Listener implementations
   void OnBadMessageReceived(const Message& message) override;
   void OnChannelError() override;
 
   scoped_ptr<Channel> channel_;
   Delegate* delegate_;
   State state_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoBootstrap);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_MOJO_IPC_MOJO_BOOTSTRAP_H_