Change preference APIs to take std::string instead of const char*.

base/prefs/scoped_user_pref_update.h

 // Copyright 2013 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.
 //
 // A helper class that assists preferences in firing notifications when lists
 // or dictionaries are changed.
 
 #ifndef BASE_PREFS_SCOPED_USER_PREF_UPDATE_H_
 #define BASE_PREFS_SCOPED_USER_PREF_UPDATE_H_
 
@@ skipping 15 matching lines @@
 namespace subtle {
 
 // Base class for ScopedUserPrefUpdateTemplate that contains the parts
 // that do not depend on ScopedUserPrefUpdateTemplate's template parameter.
 //
 // We need this base class mostly for making it a friend of PrefService
 // and getting access to PrefService::GetMutableUserPref and
 // PrefService::ReportUserPrefChanged.
 class BASE_PREFS_EXPORT ScopedUserPrefUpdateBase : public base::NonThreadSafe {
  protected:
-  ScopedUserPrefUpdateBase(PrefService* service, const char* path);
+  ScopedUserPrefUpdateBase(PrefService* service, const std::string& path);
 
   // Calls Notify().
   ~ScopedUserPrefUpdateBase();
 
   // Sets |value_| to |service_|->GetMutableUserPref and returns it.
   base::Value* GetValueOfType(base::Value::Type type);
 
  private:
   // If |value_| is not null, triggers a notification of PrefObservers and
   // resets |value_|.
@@ skipping 12 matching lines @@
 }  // namespace subtle
 
 // Class to support modifications to DictionaryValues and ListValues while
 // guaranteeing that PrefObservers are notified of changed values.
 //
 // This class may only be used on the UI thread as it requires access to the
 // PrefService.
 template <typename T, base::Value::Type type_enum_value>
 class ScopedUserPrefUpdate : public subtle::ScopedUserPrefUpdateBase {
  public:
-  ScopedUserPrefUpdate(PrefService* service, const char* path)
+  ScopedUserPrefUpdate(PrefService* service, const std::string& path)
       : ScopedUserPrefUpdateBase(service, path) {}
 
   // Triggers an update notification if Get() was called.
   virtual ~ScopedUserPrefUpdate() {}
 
   // Returns a mutable |T| instance that
   // - is already in the user pref store, or
   // - is (silently) created and written to the user pref store if none existed
   //   before.
   //
@@ skipping 19 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ScopedUserPrefUpdate);
 };
 
 typedef ScopedUserPrefUpdate<base::DictionaryValue,
                              base::Value::TYPE_DICTIONARY>
     DictionaryPrefUpdate;
 typedef ScopedUserPrefUpdate<base::ListValue, base::Value::TYPE_LIST>
     ListPrefUpdate;
 
 #endif  // BASE_PREFS_SCOPED_USER_PREF_UPDATE_H_