Remove JsonPrefStore pruning of empty values on write.

android_webview/browser/aw_pref_store.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/aw_pref_store.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 
 AwPrefStore::AwPrefStore() {}
@@ skipping 34 matching lines @@
 
 void AwPrefStore::SetValueSilently(const std::string& key, Value* value) {
   prefs_.SetValue(key, value);
 }
 
 void AwPrefStore::RemoveValue(const std::string& key) {
   if (prefs_.RemoveValue(key))
     ReportValueChanged(key);
 }
 
-void AwPrefStore::MarkNeedsEmptyValue(const std::string& key) {
-}
-
 bool AwPrefStore::ReadOnly() const {
   return false;
 }
 
 PersistentPrefStore::PrefReadError AwPrefStore::GetReadError() const {
   return PersistentPrefStore::PREF_READ_ERROR_NONE;
 }
 
 PersistentPrefStore::PrefReadError AwPrefStore::ReadPrefs() {
   return PersistentPrefStore::PREF_READ_ERROR_NONE;
 }
 
 void AwPrefStore::ReadPrefsAsync(ReadErrorDelegate* error_delegate_raw) {
 }
 
 void AwPrefStore::ReportValueChanged(const std::string& key) {
   FOR_EACH_OBSERVER(Observer, observers_, OnPrefValueChanged(key));
 }