Mojo C++ Bindings: Extract AssociatedGroupController from MultiplexRouter

mojo/public/cpp/bindings/interface_id.h

 // Copyright 2015 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_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_ID_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_ID_H_
+#ifndef MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_ID_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_ID_H_
 
 #include <stdint.h>
 
 namespace mojo {
-namespace internal {
 
 // The size of the type matters because it is directly used in messages.
 using InterfaceId = uint32_t;
 
 // IDs of associated interface can be generated at both sides of the message
 // pipe. In order to avoid collision, the highest bit is used as namespace bit:
 // at the side where the client-side of the master interface lives, IDs are
 // generated with the namespace bit set to 1; at the opposite side IDs are
 // generated with the namespace bit set to 0.
 const uint32_t kInterfaceIdNamespaceMask = 0x80000000;
 
 const InterfaceId kMasterInterfaceId = 0x00000000;
 const InterfaceId kInvalidInterfaceId = 0xFFFFFFFF;
 
 inline bool IsMasterInterfaceId(InterfaceId id) {
   return id == kMasterInterfaceId;
 }
 
 inline bool IsValidInterfaceId(InterfaceId id) {
   return id != kInvalidInterfaceId;
 }
 
-}  // namespace internal
 }  // namespace mojo
 
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_ID_H_
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_ID_H_