| Index: base/BUILD.gn | 
| diff --git a/base/BUILD.gn b/base/BUILD.gn | 
| index da08f80c74c0e46e9eff4faa76bbeefc0bf292be..bb09440051327b75ee5cf6e4b4fd28c49706edcb 100644 | 
| --- a/base/BUILD.gn | 
| +++ b/base/BUILD.gn | 
| @@ -559,6 +559,7 @@ component("base") { | 
| "numerics/safe_math_impl.h", | 
| "observer_list.h", | 
| "observer_list_threadsafe.h", | 
| +    "optional.h", | 
| "os_compat_android.cc", | 
| "os_compat_android.h", | 
| "os_compat_nacl.cc", | 
| @@ -1792,6 +1793,7 @@ test("base_unittests") { | 
| "native_library_unittest.cc", | 
| "numerics/safe_numerics_unittest.cc", | 
| "observer_list_unittest.cc", | 
| +    "optional_unittest.cc", | 
| "os_compat_android_unittest.cc", | 
| "path_service_unittest.cc", | 
| "pickle_unittest.cc", | 
|  |