Sanitize PrefStore interface.

chrome/common/json_pref_store.cc

Index: chrome/common/json_pref_store.cc
diff --git a/chrome/common/json_pref_store.cc b/chrome/common/json_pref_store.cc
index d68307f622261b919ffdd4e907c2e231955d79ac..a3fe5b8cbd7692354638dfc76efcead76f319dda 100644
--- a/chrome/common/json_pref_store.cc
+++ b/chrome/common/json_pref_store.cc
@@ -30,7 +30,40 @@ JsonPrefStore::~JsonPrefStore() {
     writer_.DoScheduledWrite();
 }
 
-PrefStore::PrefReadError JsonPrefStore::ReadPrefs() {
+PrefStore::ReadResult JsonPrefStore::GetValue(const std::string& key,
+                                              Value** result) const {
+  return prefs_->Get(key, result) ? READ_OK : READ_NO_VALUE;
+}
+
+void JsonPrefStore::SetValue(const std::string& key, Value* value) {
+  DCHECK(value);
+  scoped_ptr<Value> new_value(value);
+  Value* old_value = NULL;
+  prefs_->Get(key, &old_value);
+  if (!old_value || !value->Equals(old_value)) {
+    prefs_->Set(key, new_value.release());
+    FOR_EACH_OBSERVER(PrefStore::ObserverInterface, observers_,
+                      OnPrefValueChanged(key));
+  }
+}
+
+void JsonPrefStore::SetValueSilently(const std::string& key, Value* value) {
+  DCHECK(value);
+  scoped_ptr<Value> new_value(value);
+  Value* old_value = NULL;
+  prefs_->Get(key, &old_value);
+  if (!old_value || !value->Equals(old_value))
+    prefs_->Set(key, new_value.release());
+}
+
+void JsonPrefStore::RemoveValue(const std::string& key) {
+  if (prefs_->Remove(key, NULL)) {
+    FOR_EACH_OBSERVER(PrefStore::ObserverInterface, observers_,
+                      OnPrefValueChanged(key));
+  }
+}
+
+PersistentPrefStore::PrefReadError JsonPrefStore::ReadPrefs() {
   if (path_.empty()) {
     read_only_ = true;
     return PREF_READ_ERROR_FILE_NOT_SPECIFIED;
@@ -131,3 +164,11 @@ bool JsonPrefStore::SerializeData(std::string* output) {
   scoped_ptr<DictionaryValue> copy(prefs_->DeepCopyWithoutEmptyChildren());
   return serializer.Serialize(*(copy.get()));
 }
+
+void JsonPrefStore::AddObserver(PrefStore::ObserverInterface* observer) {
+  observers_.AddObserver(observer);
+}
+
+void JsonPrefStore::RemoveObserver(PrefStore::ObserverInterface* observer) {
+  observers_.RemoveObserver(observer);
+}