chrome.settingsPrivate: Implement onPrefsChanged event handling.

chrome/browser/extensions/api/settings_private/prefs_util.h

+// Copyright 2015 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_EXTENSIONS_API_SETTINGS_PRIVATE_PREFS_UTIL_H_
+#define CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_PREFS_UTIL_H_
+
+#include <map>
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/common/extensions/api/settings_private.h"
+
+class PrefService;
+class Profile;
+
+namespace extensions {
+
+namespace prefs_util {
+
+using TypedPrefMap = std::map<std::string, api::settings_private::PrefType>;
+
+const TypedPrefMap& GetWhitelistedKeys();

[stevenjb, 2015/04/06 22:40:59]

All of these functions should have comments.

[Oren Blasberg, 2015/04/06 23:27:06]

Done.

+
+// Gets the value of the pref with the given |name|.

[stevenjb, 2015/04/06 22:40:59]

Describe behavior if |name| is not found. (i.e. Returns a default pref object.
as opposed to a null ptr value which might be expected).

[Oren Blasberg, 2015/04/06 23:27:06]

Done.

+scoped_ptr<api::settings_private::PrefObject> GetPref(Profile* profile,
+                                                      const std::string& name);
+
+bool IsPrefTypeURL(const std::string& pref_name);
+
+bool IsPrefUserModifiable(Profile* profile, const std::string& pref_name);
+
+PrefService* FindServiceForPref(Profile* profile, const std::string& pref_name);
+
+}  // namespace prefs_util
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_PREFS_UTIL_H_