Remove JsonPrefStore pruning of empty values on write.

base/prefs/json_pref_store.cc

Index: base/prefs/json_pref_store.cc
diff --git a/base/prefs/json_pref_store.cc b/base/prefs/json_pref_store.cc
index e230407043aea5ebc29056618ece54571e274b9c..ad97b8459cb1c5c614f021d2a24408c10e9c3df3 100644
--- a/base/prefs/json_pref_store.cc
+++ b/base/prefs/json_pref_store.cc
@@ -217,14 +217,10 @@ void JsonPrefStore::SetValueSilently(const std::string& key,
 }
 
 void JsonPrefStore::RemoveValue(const std::string& key) {
-  if (prefs_->Remove(key, NULL))
+  if (prefs_->RemovePath(key, NULL))
     ReportValueChanged(key);
 }
 
-void JsonPrefStore::MarkNeedsEmptyValue(const std::string& key) {
-  keys_need_empty_value_.insert(key);
-}
-
 bool JsonPrefStore::ReadOnly() const {
   return read_only_;
 }
@@ -324,35 +320,7 @@ JsonPrefStore::~JsonPrefStore() {
 }
 
 bool JsonPrefStore::SerializeData(std::string* output) {
-  // TODO(tc): Do we want to prune webkit preferences that match the default
-  // value?
   JSONStringValueSerializer serializer(output);
   serializer.set_pretty_print(true);
-  scoped_ptr<base::DictionaryValue> copy(
-      prefs_->DeepCopyWithoutEmptyChildren());
-
-  // Iterates |keys_need_empty_value_| and if the key exists in |prefs_|,
-  // ensure its empty ListValue or DictonaryValue is preserved.
-  for (std::set<std::string>::const_iterator
-       it = keys_need_empty_value_.begin();
-       it != keys_need_empty_value_.end();
-       ++it) {
-    const std::string& key = *it;
-
-    base::Value* value = NULL;
-    if (!prefs_->Get(key, &value))
-      continue;
-
-    if (value->IsType(base::Value::TYPE_LIST)) {
-      const base::ListValue* list = NULL;
-      if (value->GetAsList(&list) && list->empty())
-        copy->Set(key, new base::ListValue);
-    } else if (value->IsType(base::Value::TYPE_DICTIONARY)) {
-      const base::DictionaryValue* dict = NULL;
-      if (value->GetAsDictionary(&dict) && dict->empty())
-        copy->Set(key, new base::DictionaryValue);
-    }
-  }
-
-  return serializer.Serialize(*(copy.get()));
+  return serializer.Serialize(*prefs_);
 }