Make ScopedGeneric uses slightly more consistent

util/win/scoped_local_alloc.h

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #ifndef CRASHPAD_UTIL_WIN_SCOPED_LOCAL_ALLOC_H_
 #define CRASHPAD_UTIL_WIN_SCOPED_LOCAL_ALLOC_H_
 
 #include <windows.h>
 
 #include "base/scoped_generic.h"
 
 namespace crashpad {
 
+namespace internal {
+
 struct LocalAllocTraits {
   static HLOCAL InvalidValue() { return nullptr; }
   static void Free(HLOCAL mem);
 };
 
-using ScopedLocalAlloc = base::ScopedGeneric<HLOCAL, LocalAllocTraits>;
+}  // namespace internal
+
+using ScopedLocalAlloc =
+    base::ScopedGeneric<HLOCAL, internal::LocalAllocTraits>;
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_WIN_SCOPED_LOCAL_ALLOC_H_