Mojo: Add a "GetType()" to Dispatchers.

mojo/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_SYSTEM_DISPATCHER_H_
 #define MOJO_SYSTEM_DISPATCHER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "mojo/public/system/core.h"
 #include "mojo/system/system_impl_export.h"
 
 namespace mojo {
 namespace system {
 
 class CoreImpl;
 class Waiter;
 
 // A |Dispatcher| implements Mojo primitives that are "attached" to a particular
 // handle. This includes most (all?) primitives except for |MojoWait...()|. This
 // object is thread-safe, with its state being protected by a single lock
 // |lock_|, which is also made available to implementation subclasses (via the
 // |lock()| method).
 class MOJO_SYSTEM_IMPL_EXPORT Dispatcher :
     public base::RefCountedThreadSafe<Dispatcher> {
  public:
+  enum Type {
+    kTypeUnknown = 0,
+    kTypeMessagePipe,
+    kTypeDataPipeProducer,
+    kTypeDataPipeConsumer
+  };
+  virtual Type GetType() = 0;
+
   // These methods implement the various primitives named |Mojo...()|. These
   // take |lock_| and handle races with |Close()|. Then they call out to
   // subclasses' |...ImplNoLock()| methods (still under |lock_|), which actually
   // implement the primitives.
   // NOTE(vtl): This puts a big lock around each dispatcher (i.e., handle), and
   // prevents the various |...ImplNoLock()|s from releasing the lock as soon as
   // possible. If this becomes an issue, we can rethink this.
   MojoResult Close();
   // |dispatchers| may be non-null if and only if there are handles to be
   // written, in which case this will be called with all the dispatchers' locks
@@ skipping 124 matching lines @@
   mutable base::Lock lock_;
   bool is_closed_;
 
   DISALLOW_COPY_AND_ASSIGN(Dispatcher);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_DISPATCHER_H_