Implement chrome.systemPrivate.getIncognitoModeAvailability extension API function

chrome/browser/extensions/extension_system_api.h

+// Copyright (c) 2011 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.
+
+// This is a dumping ground for APIs that are provided for component extensions

[Aaron Boodman, 2011/11/28 19:32:44]

I don't think this comment is accurate. 'system' is a reasonable enough
namespace for a method that determines whether incognito is available.

+// that shall not be exposed publicly. In case any of this functionality
+// has to be made available for all extensions, it should be moved to a
+// proper namespace.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_API_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_API_H_
+
+#include "chrome/browser/extensions/extension_preference_api.h"
+
+#include <string>
+
+namespace base {
+class Value;
+}
+
+// Transforms the internal numeric representation of
+// prefs::kIncognitoModeAvailability into strings exposed to extensions.
+class IncognitoModeAvailabilityTransformer : public PrefTransformerInterface {
+ public:
+  IncognitoModeAvailabilityTransformer();
+  virtual ~IncognitoModeAvailabilityTransformer();
+
+  virtual base::Value* ExtensionToBrowserPref(
+      const base::Value* extension_pref,
+      std::string* error,
+      bool* bad_message) OVERRIDE;
+
+  virtual base::Value* BrowserToExtensionPref(
+      const base::Value* browser_pref) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(IncognitoModeAvailabilityTransformer);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_API_H_