Add the ability to get the current directory

runtime/bin/directory.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 "bin/directory.h"
 
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
 
 dart::Mutex Directory::mutex_;
 int Directory::service_ports_size_ = 0;
 Dart_Port* Directory::service_ports_ = NULL;
 int Directory::service_ports_index_ = 0;
 
+void FUNCTION_NAME(Directory_Current)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  char* current = Directory::Current();
+  if (current != NULL) {
+    Dart_SetReturnValue(args, Dart_NewString(current));
+    free(current);
+  }
+  Dart_ExitScope();
+}
+
+
 void FUNCTION_NAME(Directory_Exists)(Dart_NativeArguments args) {
   static const int kError = -1;
   static const int kExists = 1;
   static const int kDoesNotExist = 0;
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 0);
   if (Dart_IsString(path)) {
     Directory::ExistsResult result =
         Directory::Exists(DartUtils::GetStringValue(path));
     int return_value = kError;
@@ skipping 270 matching lines @@
   return Dart_PostCObject(response_port_, response->AsApiCObject());
 }
 
 
 bool DirectoryListing::HandleError(char* message) {
   // TODO(sgjesse): Pass flags to indicate whether error
   // responses are needed.
   CObjectArray* response = NewResponse(kListError, message);
   return Dart_PostCObject(response_port_, response->AsApiCObject());
 }