Add KeepAliveStateObserver, add the Restart option

chrome/browser/lifetime/scoped_keep_alive.h

 // Copyright 2016 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_LIFETIME_SCOPED_KEEP_ALIVE_H_
 #define CHROME_BROWSER_LIFETIME_SCOPED_KEEP_ALIVE_H_
 
 #include "base/macros.h"
 
 namespace keep_alive {
 enum class Origin;
+enum class RestartOption;
 }
 
 // Registers with KeepAliveRegistry on creation and unregisters them
 // on destruction. Use these objects with a scoped_ptr for easy management.
 class ScopedKeepAlive {
  public:
-  explicit ScopedKeepAlive(keep_alive::Origin origin);
+  ScopedKeepAlive(keep_alive::Origin origin, keep_alive::RestartOption restart);
   ~ScopedKeepAlive();
 
  private:
   const keep_alive::Origin origin_;
+  const keep_alive::RestartOption restart_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedKeepAlive);
 };
 
 #endif  // CHROME_BROWSER_LIFETIME_SCOPED_KEEP_ALIVE_H_