Revert of Move base/prefs to components/prefs

base/prefs/default_pref_store_unittest.cc

Index: base/prefs/default_pref_store_unittest.cc
diff --git a/base/prefs/default_pref_store_unittest.cc b/base/prefs/default_pref_store_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..597ca558a4f7ac6f1b5bc8b3a2b4a46f4785133b
--- /dev/null
+++ b/base/prefs/default_pref_store_unittest.cc
@@ -0,0 +1,70 @@
+// Copyright (c) 2012 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 "base/macros.h"
+#include "base/prefs/default_pref_store.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using base::StringValue;
+using base::Value;
+
+namespace {
+
+class MockPrefStoreObserver : public PrefStore::Observer {
+ public:
+  explicit MockPrefStoreObserver(DefaultPrefStore* pref_store);
+  ~MockPrefStoreObserver() override;
+
+  int change_count() {
+    return change_count_;
+  }
+
+  // PrefStore::Observer implementation:
+  void OnPrefValueChanged(const std::string& key) override;
+  void OnInitializationCompleted(bool succeeded) override {}
+
+ private:
+  DefaultPrefStore* pref_store_;
+
+  int change_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(MockPrefStoreObserver);
+};
+
+MockPrefStoreObserver::MockPrefStoreObserver(DefaultPrefStore* pref_store)
+    : pref_store_(pref_store), change_count_(0) {
+  pref_store_->AddObserver(this);
+}
+
+MockPrefStoreObserver::~MockPrefStoreObserver() {
+  pref_store_->RemoveObserver(this);
+}
+
+void MockPrefStoreObserver::OnPrefValueChanged(const std::string& key) {
+  change_count_++;
+}
+
+}  // namespace
+
+TEST(DefaultPrefStoreTest, NotifyPrefValueChanged) {
+  scoped_refptr<DefaultPrefStore> pref_store(new DefaultPrefStore);
+  MockPrefStoreObserver observer(pref_store.get());
+  std::string kPrefKey("pref_key");
+
+  // Setting a default value shouldn't send a change notification.
+  pref_store->SetDefaultValue(kPrefKey,
+                              scoped_ptr<Value>(new StringValue("foo")));
+  EXPECT_EQ(0, observer.change_count());
+
+  // Replacing the default value should send a change notification...
+  pref_store->ReplaceDefaultValue(kPrefKey,
+                                  scoped_ptr<Value>(new StringValue("bar")));
+  EXPECT_EQ(1, observer.change_count());
+
+  // But only if the value actually changed.
+  pref_store->ReplaceDefaultValue(kPrefKey,
+                                  scoped_ptr<Value>(new StringValue("bar")));
+  EXPECT_EQ(1, observer.change_count());
+}
+