Change File.directory to not do any IO

runtime/bin/file_macos.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_MACOS)
 
 #include "bin/file.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 265 matching lines @@
     ASSERT(resolved_path != NULL);
     do {
       abs_path = realpath(pathname, NULL);
     } while (abs_path == NULL && errno == EINTR);
     ASSERT(abs_path == NULL || IsAbsolutePath(abs_path));
   }
   return abs_path;
 }
 
 
-char* File::GetContainingDirectory(char* pathname) {
-  // Report errors for non-regular files.
-  struct stat st;
-  if (TEMP_FAILURE_RETRY(stat(pathname, &st)) == 0) {
-    if (!S_ISREG(st.st_mode)) {
-      errno = (S_ISDIR(st.st_mode)) ? EISDIR : ENOENT;
-      return NULL;
-    }
-  } else {
-    return NULL;
-  }
-  char* path = NULL;
-  do {
-    path = dirname(pathname);
-  } while (path == NULL && errno == EINTR);
-  return GetCanonicalPath(path);
-}
-
-
 const char* File::PathSeparator() {
   return "/";
 }
 
 
 const char* File::StringEscapedPathSeparator() {
   return "/";
 }
 
 
@@ skipping 38 matching lines @@
   return (file_1_info.st_ino == file_2_info.st_ino &&
           file_1_info.st_dev == file_2_info.st_dev) ?
       File::kIdentical :
       File::kDifferent;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)