Remove JsonPrefStore pruning of empty values on write.

base/prefs/pref_service.cc

Index: base/prefs/pref_service.cc
diff --git a/base/prefs/pref_service.cc b/base/prefs/pref_service.cc
index 4c707a50d6c231137055bf27b7930f945aa3045e..f02abc02c27c9cd1bb75916f4b0f1f05a93a0638 100644
--- a/base/prefs/pref_service.cc
+++ b/base/prefs/pref_service.cc
@@ -297,10 +297,6 @@ const base::Value* PrefService::GetDefaultPrefValue(const char* path) const {
   return value;
 }
 
-void PrefService::MarkUserStoreNeedsEmptyValue(const std::string& key) const {
-  user_pref_store_->MarkNeedsEmptyValue(key);
-}
-
 const base::ListValue* PrefService::GetList(const char* path) const {
   DCHECK(CalledOnValidThread());
 
@@ -349,23 +345,7 @@ void PrefService::AddRegisteredPreference(const char* path,
                                           base::Value* default_value) {
   DCHECK(CalledOnValidThread());
 
-  // For ListValue and DictionaryValue with non empty default, empty value
-  // for |path| needs to be persisted in |user_pref_store_|. So that
-  // non empty default is not used when user sets an empty ListValue or
-  // DictionaryValue.
-  bool needs_empty_value = false;
-  base::Value::Type orig_type = default_value->GetType();
-  if (orig_type == base::Value::TYPE_LIST) {
-    const base::ListValue* list = NULL;
-    if (default_value->GetAsList(&list) && !list->empty())
-      needs_empty_value = true;
-  } else if (orig_type == base::Value::TYPE_DICTIONARY) {
-    const base::DictionaryValue* dict = NULL;
-    if (default_value->GetAsDictionary(&dict) && !dict->empty())
-      needs_empty_value = true;
-  }
-  if (needs_empty_value)
-    user_pref_store_->MarkNeedsEmptyValue(path);
+  //REMOVE?

[Mattias Nissler (ping if slow), 2013/11/22 08:03:38]

Yes, as well as PrefService::AddInitialPreferences and
PrefRegistry::SetRegistrationCallback.

[gab, 2013/11/22 23:24:21]

Hmmm interesting that I didn't get a PRESUBMIT check when uploading this... I
usually put comments with no space as notes to myself to be handled before
upload... somehow this made it up despite my intention of cleaning this up after
merging.

Thanks for clarifying what to remove, done.

 }
 
 void PrefService::ClearPref(const char* path) {