Implement chrome.systemPrivate.getIncognitoModeAvailability extension API function

chrome/browser/extensions/system/system_api.cc

Index: chrome/browser/extensions/system/system_api.cc
diff --git a/chrome/browser/extensions/system/system_api.cc b/chrome/browser/extensions/system/system_api.cc
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--- /dev/null
+++ b/chrome/browser/extensions/system/system_api.cc
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+// 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.
+
+#include "chrome/browser/extensions/system/system_api.h"
+
+#include "base/values.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/pref_names.h"
+
+namespace {
+
+// Maps prefs::kIncognitoModeAvailability values (0 = enabled, ...)
+// to strings exposed to extensions.
+const char* kIncognitoModeAvailabilityStrings[] = {
+  "enabled",
+  "disabled",
+  "forced"
+};
+
+}  // namespace
+
+namespace extensions {
+
+GetIncognitoModeAvailabilityFunction::~GetIncognitoModeAvailabilityFunction() {
+}
+
+bool GetIncognitoModeAvailabilityFunction::RunImpl() {
+  PrefService* prefs = profile_->GetPrefs();
+  int value = prefs->GetInteger(prefs::kIncognitoModeAvailability);
+  EXTENSION_FUNCTION_VALIDATE(
+      value >= 0 &&
+      value < static_cast<int>(arraysize(kIncognitoModeAvailabilityStrings)));
+  result_.reset(
+      Value::CreateStringValue(kIncognitoModeAvailabilityStrings[value]));
+  return true;
+}
+
+}  // namespace extensions