Add property base to the Uri class

runtime/lib/uri.cc

 // Copyright (c) 2013, 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/utils.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 
 namespace dart {
 
 DEFINE_NATIVE_ENTRY(Uri_isWindowsPlatform, 0) {
-#if defined(_WIN32)
+#if defined(TARGET_OS_WINDOWS)
   return Bool::True().raw();
 #else
   return Bool::False().raw();
 #endif
 }
 
+
+DEFINE_NATIVE_ENTRY(Uri_currentDirectory, 0) {
+  char* current = bin::Directory::Current();
+  if (current == NULL) {
+    bin::OSError err;
+    const String& error = String::Handle(String::NewFormatted(
+        "Error determining current directory: %s", err.message()));
+    const Array& args = Array::Handle(Array::New(1));
+    args.SetAt(0, error);
+    Exceptions::ThrowByType(Exceptions::kUnsupported, args);
+  }
+
+  const String& result = String::Handle(String::New(current));
+  return result.raw();
+}
+
 }  // namespace dart