win: Add implementation of system_snapshot for Windows

snapshot/system_snapshot.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 20 matching lines @@
  public:
   virtual ~SystemSnapshot() {}
 
   //! \brief A system’s operating system family.
   enum OperatingSystem {
     //! \brief The snapshot system’s operating system is unknown.
     kOperatingSystemUnknown = 0,
 
     //! \brief Mac OS X.
     kOperatingSystemMacOSX,
+
+    //! \brief Windows.
+    kOperatingSystemWindows,
   };
 
   //! \brief A system’s daylight saving time status.
   //!
   //! The daylight saving time status is taken partially from the system’s
   //! locale configuration. This determines whether daylight saving time is
   //! ever observed on the system. If it is, the snapshot’s time
   //! (ProcessSnapshot::SnapshotTime()) is used to determine whether the system
   //! was observing daylight saving time at the time of the snapshot.
   enum DaylightSavingTimeStatus {
@@ skipping 207 matching lines @@
   virtual void TimeZone(DaylightSavingTimeStatus* observes_daylight,
                         int* standard_offset_seconds,
                         int* daylight_offset_seconds,
                         std::string* standard_name,
                         std::string* daylight_name) const = 0;
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_SYSTEM_SNAPSHOT_H_