Add multiplexing of message pipes in the new EDK.

mojo/edk/system/dispatcher.h

 // Copyright 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.
 
 #ifndef MOJO_EDK_SYSTEM_DISPATCHER_H_
 #define MOJO_EDK_SYSTEM_DISPATCHER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 282 matching lines @@
   virtual void TransportEnded() {}
 
   // This should be overridden to return true if/when there's an ongoing
   // operation (e.g., two-phase read/writes on data pipes) that should prevent a
   // handle from being sent over a message pipe (with status "busy").
   virtual bool IsBusyNoLock() const;
 
   // Available to subclasses. (Note: Returns a non-const reference, just like
   // |base::AutoLock|'s constructor takes a non-const reference.)
   base::Lock& lock() const { return lock_; }
+  bool is_closed() const { return is_closed_; }
 
  private:
   friend class DispatcherTransport;
 
   // Closes the dispatcher. This must be done under lock, and unlike |Close()|,
   // the dispatcher must not be closed already. (This is the "equivalent" of
   // |CreateEquivalentDispatcherAndCloseNoLock()|, for situations where the
   // dispatcher must be disposed of instead of "transferred".)
   void CloseNoLock();
 
@@ skipping 79 matching lines @@
 // So logging macros and |DCHECK_EQ()|, etc. work.
 MOJO_SYSTEM_IMPL_EXPORT inline std::ostream& operator<<(std::ostream& out,
                                                         Dispatcher::Type type) {
   return out << static_cast<int>(type);
 }
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_DISPATCHER_H_