run iwyu on base!

base/sha2.cc

 // Copyright (c) 2006-2008 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/sha2.h"
+#include <stddef.h>
+#include <string>
 
 #include "base/stl_util-inl.h"
 #include "base/third_party/nss/blapi.h"
-#include "base/third_party/nss/sha256.h"
+#include "base/third_party/nss/blapit.h"
 
 namespace base {
 
 void SHA256HashString(const std::string& str, void* output, size_t len) {
   SHA256Context ctx;
 
   SHA256_Begin(&ctx);
   SHA256_Update(&ctx, reinterpret_cast<const unsigned char*>(str.data()),
                 static_cast<unsigned int>(str.length()));
   SHA256_End(&ctx, static_cast<unsigned char*>(output), NULL,
              static_cast<unsigned int>(len));
 }
 
 std::string SHA256HashString(const std::string& str) {
   std::string output(SHA256_LENGTH, 0);
   SHA256HashString(str, string_as_array(&output), output.size());
   return output;
 }
 
 }  // namespace base