Move PrefRegistrySimple to use unique_ptr<Value>

components/prefs/pref_registry.h

Index: components/prefs/pref_registry.h
diff --git a/components/prefs/pref_registry.h b/components/prefs/pref_registry.h
index 31a4956f7937ecda8442d69a2ef17bf08ff7af6b..bdb8af55a0442560cbe6231fd24e03cc0382be10 100644
--- a/components/prefs/pref_registry.h
+++ b/components/prefs/pref_registry.h
@@ -7,6 +7,8 @@
 
 #include <stdint.h>
 
+#include <memory>
+
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ -75,7 +77,7 @@ class COMPONENTS_PREFS_EXPORT PrefRegistry
   // Used by subclasses to register a default value and registration flags for
   // a preference. |flags| is a bitmask of |PrefRegistrationFlags|.
   void RegisterPreference(const std::string& path,
-                          base::Value* default_value,
+                          std::unique_ptr<base::Value> default_value,
                           uint32_t flags);
 
   scoped_refptr<DefaultPrefStore> defaults_;