iwyu: Cleanup in the following files:

base/atomicops_unittest.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #include "base/atomicops.h"
+
+#include <string.h>
+
+#include "base/port.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 template <class AtomicType>
 static void TestAtomicIncrement() {
   // For now, we just test single threaded execution
 
   // use a guard value to make sure the NoBarrier_AtomicIncrement doesn't go
   // outside the expected address bounds.  This is in particular to
   // test that some future change to the asm code doesn't cause the
   // 32-bit NoBarrier_AtomicIncrement doesn't do the wrong thing on 64-bit
@@ skipping 212 matching lines @@
 
 TEST(AtomicOpsTest, Store) {
   TestStore<base::subtle::Atomic32>();
   TestStore<base::subtle::AtomicWord>();
 }
 
 TEST(AtomicOpsTest, Load) {
   TestLoad<base::subtle::Atomic32>();
   TestLoad<base::subtle::AtomicWord>();
 }