win: Implement CrashpadClient::StartHandler()

client/crashpad_client.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 128 matching lines @@
   //! \note This is provided as a static function to allow it to be used in
   //!     situations where a CrashpadClient object is not otherwise available.
   //!     This may be useful when a child process inherits its parent’s Crashpad
   //!     handler, but wants to sever this tie.
   static void UseSystemDefaultHandler();
 #endif
 
  private:
 #if defined(OS_MACOSX)
   base::mac::ScopedMachSendRight exception_port_;
+#elif defined(OS_WIN)
+  std::string ipc_port_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(CrashpadClient);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_CLIENT_CRASHPAD_CLIENT_H_