Switch //components away from base::ListValue::Append(Value*) overload.

components/spellcheck/browser/spellcheck_action.cc

Index: components/spellcheck/browser/spellcheck_action.cc
diff --git a/components/spellcheck/browser/spellcheck_action.cc b/components/spellcheck/browser/spellcheck_action.cc
index 55ac779fd973b397776076b4249119c37cca9fec..f34001b8fd9d94fd6b12f42fe221114de403f5a5 100644
--- a/components/spellcheck/browser/spellcheck_action.cc
+++ b/components/spellcheck/browser/spellcheck_action.cc
@@ -39,8 +39,8 @@ void SpellcheckAction::Finalize() {
   }
 }
 
-base::DictionaryValue* SpellcheckAction::Serialize() const {
-  base::DictionaryValue* result = new base::DictionaryValue;
+std::unique_ptr<base::DictionaryValue> SpellcheckAction::Serialize() const {
+  std::unique_ptr<base::DictionaryValue> result(new base::DictionaryValue);
   switch (type_) {
     case TYPE_SELECT:
       result->SetString("actionType", "SELECT");