Use a direct include of strings headers in chrome/common/, part 1.

chrome/common/extensions/feature_switch.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 "chrome/common/extensions/feature_switch.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/field_trial.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "chrome/common/chrome_switches.h"
 
 namespace extensions {
 
 namespace {
 
 class CommonSwitches {
  public:
   CommonSwitches()
       : action_box(
@@ skipping 118 matching lines @@
 
 void FeatureSwitch::SetOverrideValue(OverrideValue override_value) {
   override_value_ = override_value;
 }
 
 FeatureSwitch::OverrideValue FeatureSwitch::GetOverrideValue() const {
   return override_value_;
 }
 
 }  // namespace extensions