Clean up pref change notification handling.

chrome/browser/prefs/pref_observer_mock.h

+// 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.
+
+#ifndef CHROME_BROWSER_PREFS_PREF_OBSERVER_MOCK_H_
+#define CHROME_BROWSER_PREFS_PREF_OBSERVER_MOCK_H_
+#pragma once
+
+#include <string>
+
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/common/notification_details.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_source.h"
+#include "chrome/common/notification_type.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+using testing::Pointee;
+using testing::Property;
+using testing::Truly;
+
+// Matcher that checks whether the current value of the preference named
+// |pref_name| in |prefs| matches |value|. If |value| is NULL, the matcher
+// checks that the value is not set.
+MATCHER_P3(PrefValueMatches, prefs, pref_name, value, "") {
+  const PrefService::Preference* pref =
+      prefs->FindPreference(pref_name.c_str());
+  if (!pref)
+    return false;
+
+  const Value* actual_value = pref->GetValue();
+  if (!actual_value)
+    return value == NULL;
+  if (!value)
+    return actual_value == NULL;
+  return value->Equals(actual_value);
+}
+
+// A mock for testing preference notifications and easy setup of expectations.
+class PrefObserverMock : public NotificationObserver {
+ public:
+  PrefObserverMock() {}
+  virtual ~PrefObserverMock() {}
+
+  MOCK_METHOD3(Observe, void(NotificationType type,
+                             const NotificationSource& source,
+                             const NotificationDetails& details));
+
+  void Expect(const PrefService* prefs,
+              const std::string& pref_name,
+              const Value* value) {
+    EXPECT_CALL(*this, Observe(NotificationType(NotificationType::PREF_CHANGED),
+                               Source<PrefService>(prefs),
+                               Property(&Details<std::string>::ptr,
+                                        Pointee(pref_name))))
+        .With(PrefValueMatches(prefs, pref_name, value));
+  }
+};
+
+#endif  // CHROME_BROWSER_PREFS_PREF_OBSERVER_MOCK_H_