Add Directory.systemTemp getter to replace createSystemTemp().

runtime/bin/directory_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/directory.h"
 #include "bin/file.h"
 #include "bin/utils.h"
@@ skipping 365 matching lines @@
       GetLastError() == ERROR_ALREADY_EXISTS &&
       ExistsHelper(system_name) == EXISTS) {
     free(const_cast<wchar_t*>(system_name));
     return true;
   }
   free(const_cast<wchar_t*>(system_name));
   return (create_status != 0);
 }
 
 
-char* Directory::CreateTemp(const char* const_template, bool system) {
-  // Returns a new, unused directory name, modifying the contents of
-  // dir_template.  Creates this directory, with a default security
+char* Directory::SystemTemp() {
+  PathBuffer path;
+  path.Reset(GetTempPathW(MAX_PATH, path.AsStringW()) - 1);  // Remove \ at end.
+  return path.AsString();
+}
+
+char* Directory::CreateTemp(const char* prefix) {
+  // Returns a new, unused directory name, adding characters to the
+  // end of prefix.
+  // Creates this directory, with a default security
   // descriptor inherited from its parent directory.
   // The return value must be freed by the caller.
   PathBuffer path;
-  if (system) {
-    path.Reset(GetTempPathW(MAX_PATH, path.AsStringW()));
-    if (path.length() == 0) {
-      return NULL;
-    }
-  }
-  const wchar_t* system_template = StringUtils::Utf8ToWide(const_template);
-  path.AddW(system_template);
-  free(const_cast<wchar_t*>(system_template));
+  const wchar_t* system_prefix = StringUtils::Utf8ToWide(prefix);
+  path.AddW(system_prefix);
+  free(const_cast<wchar_t*>(system_prefix));
 
   // Length of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx is 36.
   if (path.length() > MAX_PATH - 36) {
     return NULL;
   }
 
   UUID uuid;
   RPC_STATUS status = UuidCreateSequential(&uuid);
   if (status != RPC_S_OK && status != RPC_S_UUID_LOCAL_ONLY) {
     return NULL;
@@ skipping 53 matching lines @@
       MoveFileExW(system_path, system_new_path, flags);
   free(const_cast<wchar_t*>(system_path));
   free(const_cast<wchar_t*>(system_new_path));
   return (move_status != 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)