Create a DefaultPrefStore to hold registered application-default preference v...

chrome/browser/prefs/pref_service_unittest.cc

 // Copyright (c) 2010 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 <string>
 
 #include "app/test/data/resource.h"
 #include "base/scoped_ptr.h"
 #include "base/values.h"
 #include "chrome/browser/prefs/dummy_pref_store.h"
@@ skipping 194 matching lines @@
 };
 
 const char PrefServiceSetValueTest::name_[] = "name";
 const char PrefServiceSetValueTest::value_[] = "value";
 
 TEST_F(PrefServiceSetValueTest, SetStringValue) {
   const char default_string[] = "default";
   scoped_ptr<Value> default_value(Value::CreateStringValue(default_string));
   prefs_.RegisterStringPref(name_, default_string);
   prefs_.AddPrefObserver(name_, &observer_);
+  // Changing the controlling store from default to user triggers notification.
+  SetExpectPrefChanged();
+  prefs_.Set(name_, *default_value);
+  Mock::VerifyAndClearExpectations(&observer_);
+
   SetExpectNoNotification();
   prefs_.Set(name_, *default_value);
   Mock::VerifyAndClearExpectations(&observer_);
 
   scoped_ptr<Value> new_value(Value::CreateStringValue(value_));
   SetExpectPrefChanged();
   prefs_.Set(name_, *new_value);
   EXPECT_EQ(value_, prefs_.GetString(name_));
 
   prefs_.RemovePrefObserver(name_, &observer_);
 }
 
 TEST_F(PrefServiceSetValueTest, SetDictionaryValue) {
   prefs_.RegisterDictionaryPref(name_);
   prefs_.AddPrefObserver(name_, &observer_);
 
+  // Dictionary values are special: setting one to NULL is the same as clearing
+  // the user value, allowing the NULL default to take (or keep) control.
   SetExpectNoNotification();
   prefs_.Set(name_, *null_value_);
   Mock::VerifyAndClearExpectations(&observer_);
 
   DictionaryValue new_value;
   new_value.SetString(name_, value_);
   SetExpectPrefChanged();
   prefs_.Set(name_, new_value);
   Mock::VerifyAndClearExpectations(&observer_);
   DictionaryValue* dict = prefs_.GetMutableDictionary(name_);
@@ skipping 12 matching lines @@
   dict = prefs_.GetMutableDictionary(name_);
   EXPECT_EQ(0U, dict->size());
 
   prefs_.RemovePrefObserver(name_, &observer_);
 }
 
 TEST_F(PrefServiceSetValueTest, SetListValue) {
   prefs_.RegisterListPref(name_);
   prefs_.AddPrefObserver(name_, &observer_);
 
+  // List values are special: setting one to NULL is the same as clearing the
+  // user value, allowing the NULL default to take (or keep) control.
   SetExpectNoNotification();
   prefs_.Set(name_, *null_value_);
   Mock::VerifyAndClearExpectations(&observer_);
 
   ListValue new_value;
   new_value.Append(Value::CreateStringValue(value_));
   SetExpectPrefChanged();
   prefs_.Set(name_, new_value);
   Mock::VerifyAndClearExpectations(&observer_);
   ListValue* list = prefs_.GetMutableList(name_);
   ASSERT_EQ(1U, list->GetSize());
   std::string out_value;
   list->GetString(0, &out_value);
   EXPECT_EQ(value_, out_value);
 
   SetExpectNoNotification();
   prefs_.Set(name_, new_value);
   Mock::VerifyAndClearExpectations(&observer_);
 
   SetExpectPrefChanged();
   prefs_.Set(name_, *null_value_);
   Mock::VerifyAndClearExpectations(&observer_);
   list = prefs_.GetMutableList(name_);
   EXPECT_EQ(0U, list->GetSize());
 
   prefs_.RemovePrefObserver(name_, &observer_);
 }