win: Capture some CRITICAL_SECTION debugging data

util/win/registration_protocol_win.h

 // Copyright 2015 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 31 matching lines @@
   //!     the messages or ExceptionInformation are modified incompatibly.
   enum { kMessageVersion = 1 };
 
   //! \brief Version field to detect skew between client and server. Should be
   //!     set to kMessageVersion.
   int version;
 
   //! \brief The PID of the client process.
   DWORD client_process_id;
 
-  //! \brief The address, in the client process address space, of an
+  //! \brief The address, in the client process's address space, of an
   //!     ExceptionInformation structure, used when handling a crash dump
   //!     request.
   WinVMAddress crash_exception_information;
 
-  //! \brief The address, in the client process address space, of an
+  //! \brief The address, in the client process's address space, of an
   //!     ExceptionInformation structure, used when handling a non-crashing dump
   //!     request.
   WinVMAddress non_crash_exception_information;
+
+  //! \brief The address, in the client process's address space, of a
+  //!     `CRITICAL_SECTION` allocated with a valid .DebugInfo field. This can
+  //!     be accomplished by using the
+  //!     `RTL_CRITICAL_SECTION_FLAG_FORCE_DEBUG_INFO` flag to
+  //!     `InitializeCriticalSectionEx()`. This value can be `0`, however then
+  //!     limited lock data will be available in minidumps.
+  WinVMAddress critical_section_address;
 };
 
 //! \brief A message only sent to the server by itself to trigger shutdown.
 struct ShutdownRequest {
   //! \brief A randomly generated token used to validate the the shutdown
   //!     request was not sent from another process.
   uint64_t token;
 };
 
 //! \brief The message passed from client to server by
@@ skipping 50 matching lines @@
 //! CrashpadClient::SetHandler().
 //!
 //! \sa CrashpadClient::SetHandler()
 bool SendToCrashHandlerServer(const base::string16& pipe_name,
                               const ClientToServerMessage& message,
                               ServerToClientMessage* response);
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_WIN_REGISTRATION_PROTOCOL_WIN_H_