Get generate_dump compiling on Windows

minidump/minidump_system_info_writer.cc

 // 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 136 matching lines @@
     }
   } else if (cpu_architecture == kMinidumpCPUArchitectureAMD64) {
     SetCPUOtherFeatures(AMD64FeaturesFromSystemSnapshot(system_snapshot), 0);
   }
 
   MinidumpOS operating_system;
   switch (system_snapshot->GetOperatingSystem()) {
     case SystemSnapshot::kOperatingSystemMacOSX:
       operating_system = kMinidumpOSMacOSX;
       break;
+    case SystemSnapshot::kOperatingSystemWindows:
+      operating_system = kMinidumpOSWin32NT;
+      break;
     default:
       NOTREACHED();
       operating_system = kMinidumpOSUnknown;
       break;
   }
   SetOS(operating_system);
 
   SetOSType(system_snapshot->OSServer() ? kMinidumpOSTypeServer
                                         : kMinidumpOSTypeWorkstation);
 
@@ skipping 120 matching lines @@
   DCHECK_EQ(state(), kStateWritable);
 
   return file_writer->Write(&system_info_, sizeof(system_info_));
 }
 
 MinidumpStreamType MinidumpSystemInfoWriter::StreamType() const {
   return kMinidumpStreamTypeSystemInfo;
 }
 
 }  // namespace crashpad