Make Dispatcher::Type an enum class.

mojo/edk/system/message_pipe_dispatcher.cc

Index: mojo/edk/system/message_pipe_dispatcher.cc
diff --git a/mojo/edk/system/message_pipe_dispatcher.cc b/mojo/edk/system/message_pipe_dispatcher.cc
index a6733dbe324dfb1f4c118cfa5648390834db2c1b..95faede941721e0a6894f1d2cd01b1186afde178 100644
--- a/mojo/edk/system/message_pipe_dispatcher.cc
+++ b/mojo/edk/system/message_pipe_dispatcher.cc
@@ -68,7 +68,7 @@ void MessagePipeDispatcher::Init(scoped_refptr<MessagePipe> message_pipe,
 }
 
 Dispatcher::Type MessagePipeDispatcher::GetType() const {
-  return kTypeMessagePipe;
+  return Type::MESSAGE_PIPE;
 }
 
 // static
@@ -223,7 +223,8 @@ bool MessagePipeDispatcher::EndSerializeAndCloseImplNoLock(
 MessagePipeDispatcherTransport::MessagePipeDispatcherTransport(
     DispatcherTransport transport)
     : DispatcherTransport(transport) {
-  DCHECK_EQ(message_pipe_dispatcher()->GetType(), Dispatcher::kTypeMessagePipe);
+  DCHECK_EQ(message_pipe_dispatcher()->GetType(),
+            Dispatcher::Type::MESSAGE_PIPE);
 }
 
 }  // namespace system