The chrome.screenlockPrivate API allows select apps to control the ChromeOS ScreenLocker.

chrome/browser/chromeos/extensions/screenlock_private_api.h

Index: chrome/browser/chromeos/extensions/screenlock_private_api.h
diff --git a/chrome/browser/chromeos/extensions/screenlock_private_api.h b/chrome/browser/chromeos/extensions/screenlock_private_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..f172262599c9f17b2f2101ef77faefa9f9d3318c
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+++ b/chrome/browser/chromeos/extensions/screenlock_private_api.h
@@ -0,0 +1,80 @@
+// Copyright (c) 2013 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_CHROMEOS_EXTENSIONS_SCREENLOCK_PRIVATE_API_H_
+#define CHROME_BROWSER_CHROMEOS_EXTENSIONS_SCREENLOCK_PRIVATE_API_H_
+
+#include "chrome/browser/extensions/api/profile_keyed_api_factory.h"
+#include "chrome/browser/extensions/chrome_extension_function.h"
+#include "chromeos/dbus/session_manager_client.h"
+
+namespace extensions {
+
+class ScreenlockPrivateGetLockedFunction : public ChromeAsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("screenlockPrivate.getLocked",
+                             SCREENLOCKPRIVATE_GETLOCKED)
+  ScreenlockPrivateGetLockedFunction();
+  virtual ~ScreenlockPrivateGetLockedFunction();
+  virtual bool RunImpl() OVERRIDE;
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockPrivateGetLockedFunction);
+};
+
+class ScreenlockPrivateSetLockedFunction : public ChromeAsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("screenlockPrivate.setLocked",
+                             SCREENLOCKPRIVATE_SETLOCKED)
+  ScreenlockPrivateSetLockedFunction();
+  virtual ~ScreenlockPrivateSetLockedFunction();
+  virtual bool RunImpl() OVERRIDE;
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockPrivateSetLockedFunction);
+};
+
+class ScreenlockPrivateShowMessageFunction
+    : public ChromeAsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("screenlockPrivate.showMessage",
+                             SCREENLOCKPRIVATE_SHOWMESSAGE)
+  ScreenlockPrivateShowMessageFunction();
+  virtual ~ScreenlockPrivateShowMessageFunction();
+  virtual bool RunImpl() OVERRIDE;
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockPrivateShowMessageFunction );
+};
+
+class ScreenlockPrivateEventRouter
+    : public extensions::ProfileKeyedAPI,
+      public chromeos::SessionManagerClient::Observer {
+ public:
+  explicit ScreenlockPrivateEventRouter(Profile* profile);
+  virtual ~ScreenlockPrivateEventRouter();
+  virtual void ScreenIsLocked() OVERRIDE;
+  virtual void ScreenIsUnlocked() OVERRIDE;
+
+  // ProfileKeyedAPI
+  static extensions::ProfileKeyedAPIFactory<ScreenlockPrivateEventRouter>*
+    GetFactoryInstance();
+  virtual void Shutdown() OVERRIDE;
+
+ private:
+  friend class extensions::ProfileKeyedAPIFactory<ScreenlockPrivateEventRouter>;
+
+  // ProfileKeyedAPI
+  static const char* service_name() {
+    return "ScreenlockPrivateEventRouter";
+  }
+  static const bool kServiceIsNULLWhileTesting = true;
+  static const bool kServiceRedirectedInIncognito = true;
+
+  void DispatchEvent(const std::string& event_name, base::Value* arg);
+
+  Profile* profile_;
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockPrivateEventRouter);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_SCREENLOCK_PRIVATE_API_H_