Convert //components/prefs from scoped_ptr to std::unique_ptr

BUG=554298
[email protected]

Review URL: https://codereview.chromium.org/1907043002

Cr-Commit-Position: refs/heads/master@{#389198}
diff --git a/components/prefs/value_map_pref_store.cc b/components/prefs/value_map_pref_store.cc
index fe2c808..15a0eb1 100644
--- a/components/prefs/value_map_pref_store.cc
+++ b/components/prefs/value_map_pref_store.cc
@@ -30,7 +30,7 @@
 }
 
 void ValueMapPrefStore::SetValue(const std::string& key,
-                                 scoped_ptr<base::Value> value,
+                                 std::unique_ptr<base::Value> value,
                                  uint32_t flags) {
   if (prefs_.SetValue(key, std::move(value)))
     FOR_EACH_OBSERVER(Observer, observers_, OnPrefValueChanged(key));
@@ -52,7 +52,7 @@
 }
 
 void ValueMapPrefStore::SetValueSilently(const std::string& key,
-                                         scoped_ptr<base::Value> value,
+                                         std::unique_ptr<base::Value> value,
                                          uint32_t flags) {
   prefs_.SetValue(key, std::move(value));
 }