Remove now-unused 'result' variable from vmservice_dartium.cc, breaks build on Windows

runtime/bin/vmservice_dartium.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/vmservice_dartium.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/eventhandler.h"
 #include "bin/platform.h"
@@ skipping 44 matching lines @@
                                             &error);
   if (!isolate) {
     fprintf(stderr, "Dart_CreateIsolate failed: %s\n", error);
     return 0;
   }
 
   Dart_EnterScope();
   Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
   Builtin::SetNativeResolver(Builtin::kIOLibrary);
 
-  Dart_Handle result;
-
   ASSERT(Dart_IsServiceIsolate(isolate));
   if (!VmService::Setup(DEFAULT_VM_SERVICE_SERVER_IP,
                         DEFAULT_VM_SERVICE_SERVER_PORT,
                         false /* running_precompiled */)) {
     fprintf(stderr,
             "Vmservice::Setup failed: %s\n", VmService::GetErrorMessage());
     isolate = NULL;
   }
   Dart_ExitScope();
   Dart_ExitIsolate();
@@ skipping 74 matching lines @@
 }
 
 /* DISALLOW_ALLOCATION */
 void VmServiceServer::operator delete(void* pointer)  {
   fprintf(stderr, "unreachable code\n");
   abort();
 }
 
 }  // namespace bin
 }  // namespace dart