Create native_viewport_service, don't build it into mojo_shell unless Android

mojo/services/view_manager/ids.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 MOJO_SERVICES_VIEW_MANAGER_IDS_H_
 #define MOJO_SERVICES_VIEW_MANAGER_IDS_H_
 
 #include "mojo/services/public/cpp/view_manager/types.h"
 #include "mojo/services/public/cpp/view_manager/util.h"
-#include "mojo/services/view_manager/view_manager_export.h"
 
 namespace mojo {
 namespace service {
 
 // Connection id is used to indicate no connection. That is, no
 // ViewManagerServiceImpl ever gets this id.
 const ConnectionSpecificId kInvalidConnectionId = 0;
 
 // TODO(sky): remove this, temporary while window manager API is in existing
 // api.
 const ConnectionSpecificId kWindowManagerConnection = 1;
 
 // Adds a bit of type safety to view ids.
-struct MOJO_VIEW_MANAGER_EXPORT ViewId {
+struct ViewId {
   ViewId(ConnectionSpecificId connection_id, ConnectionSpecificId view_id)
       : connection_id(connection_id),
         view_id(view_id) {}
   ViewId() : connection_id(0), view_id(0) {}
 
   bool operator==(const ViewId& other) const {
     return other.connection_id == connection_id &&
         other.view_id == view_id;
   }
 
@@ skipping 20 matching lines @@
 // Returns a ViewId that is reserved to indicate no view. That is, no view will
 // ever be created with this id.
 inline ViewId InvalidViewId() {
   return ViewId(kInvalidConnectionId, 0);
 }
 
 }  // namespace service
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_VIEW_MANAGER_IDS_H_