Introduce RegistrationServer.

client/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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_CLIENT_REGISTRATION_PROTOCOL_WIN_H_
+#define CRASHPAD_CLIENT_REGISTRATION_PROTOCOL_WIN_H_
+
+#include <windows.h>
+#include <stdint.h>
+
+#include "util/win/address_types.h"
+
+namespace crashpad {
+
+#pragma pack(push, 1)
+//! \brief A client registration request.
+struct RegistrationRequest {
+  //! \brief The PID of the client process.
+  DWORD client_process_id;
+  //! \brief The address, in the client process address space, of a CrashpadInfo
+  //!     structure.
+  crashpad::WinVMAddress crashpad_info_address;
+};
+#pragma pack(pop)
+
+#pragma pack(push, 1)
+//! \brief  A client registration response.
+struct RegistrationResponse {
+  //! \brief An event handle, valid in the client process, that should be

[scottmg, 2015/05/21 16:17:35]

Change handle to `HANDLE` since it's now less clear what's supposed to be in
these fields, and note why they can't be HANDLE.

[erikwright (departed), 2015/05/22 01:22:04]

Done.

+  //!     signaled to request a crash report.
+  uint32_t request_report_event;

[scottmg, 2015/05/21 16:17:35]

I think either WinVMAddress (because it's a void* in the target) or uint32_t
(because we know that only 32 bits are important) is reasonable for this.

If it comes up again we can add a WinCrossProcessHANDLE (or some better name).

[erikwright (departed), 2015/05/22 01:22:04]

Done.

+  //! \brief An event handle, valid in the client process, that will be signaled
+  //!     when the requested crash report is complete.
+  uint32_t report_complete_event;
+};
+#pragma pack(pop)
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_CLIENT_REGISTRATION_PROTOCOL_WIN_H_