Revert r43217, r43215, r43208, r43207, and r43202.

runtime/bin/platform_win.cc

 // Copyright (c) 2012, 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 "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/platform.h"
 #include "bin/log.h"
 #include "bin/socket.h"
@@ skipping 14 matching lines @@
   GetSystemInfo(&info);
   return info.dwNumberOfProcessors;
 }
 
 
 const char* Platform::OperatingSystem() {
   return "windows";
 }
 
 
-const char* Platform::LibraryExtension() {
-  return "dll";
-}
-
-
 bool Platform::LocalHostname(char *buffer, intptr_t buffer_length) {
-#if defined(PLATFORM_DISABLE_SOCKET)
-  return false;
-#else
   if (!Socket::Initialize()) return false;
   return gethostname(buffer, buffer_length) == 0;
-#endif
 }
 
 
 char** Platform::Environment(intptr_t* count) {
   wchar_t* strings = GetEnvironmentStringsW();
   if (strings == NULL) return NULL;
   wchar_t* tmp = strings;
   intptr_t i = 0;
   while (*tmp != '\0') {
     // Skip environment strings starting with "=".
@@ skipping 20 matching lines @@
   for (intptr_t i = 0; i < count; i++) {
     free(env[i]);
   }
   delete[] env;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)