| Index: mojo/edk/system/core_test_base.h
 | 
| diff --git a/mojo/edk/system/core_test_base.h b/mojo/edk/system/core_test_base.h
 | 
| index 7ed8a7ad9d6e9a3580e8a91a5a51082e8fe51589..254b60c9c4cce95ebe221c49b9c13e5c0086223c 100644
 | 
| --- a/mojo/edk/system/core_test_base.h
 | 
| +++ b/mojo/edk/system/core_test_base.h
 | 
| @@ -5,6 +5,8 @@
 | 
|  #ifndef MOJO_EDK_SYSTEM_CORE_TEST_BASE_H_
 | 
|  #define MOJO_EDK_SYSTEM_CORE_TEST_BASE_H_
 | 
|  
 | 
| +#include <stddef.h>
 | 
| +
 | 
|  #include "base/synchronization/lock.h"
 | 
|  #include "mojo/edk/embedder/embedder_internal.h"
 | 
|  #include "mojo/edk/system/test_utils.h"
 | 
| 
 |