Use a direct include of strings headers in extensions/, google_apis/, gpu/.

extensions/common/matcher/regex_set_matcher.cc

 // Copyright (c) 2012 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 "extensions/common/matcher/regex_set_matcher.h"
 
 #include "base/logging.h"
 #include "base/stl_util.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "extensions/common/matcher/substring_set_matcher.h"
 #include "third_party/re2/re2/filtered_re2.h"
 #include "third_party/re2/re2/re2.h"
 
 namespace extensions {
 
 RegexSetMatcher::RegexSetMatcher() {}
 
 RegexSetMatcher::~RegexSetMatcher() {
   DeleteSubstringPatterns();
@@ skipping 85 matching lines @@
         new StringPattern(strings_to_match[i], i));
   }
   substring_matcher_->RegisterPatterns(substring_patterns_);
 }
 
 void RegexSetMatcher::DeleteSubstringPatterns() {
   STLDeleteElements(&substring_patterns_);
 }
 
 }  // namespace extensions