Change how File/Directory/Link .delete works.

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 151 matching lines @@
 }
 
 
 bool File::CreateLink(const char* name, const char* target) {
   int status = TEMP_FAILURE_RETRY(symlink(target, name));
   return (status == 0);
 }
 
 
 bool File::Delete(const char* name) {
-  int status = TEMP_FAILURE_RETRY(remove(name));
-  if (status == -1) {
-    return false;
+  File::Type type = File::GetType(name, true);
+  if (type == kIsFile) {
+    return TEMP_FAILURE_RETRY(unlink(name)) == 0;
+  } else if (type == kIsDirectory) {
+    errno = EISDIR;
+  } else {
+    errno = ENOENT;
   }
-  return true;
+  return false;
 }
 
 
+bool File::DeleteLink(const char* name) {
+  File::Type type = File::GetType(name, false);
+  if (type == kIsLink) {
+    return TEMP_FAILURE_RETRY(unlink(name)) == 0;
+  }
+  errno = EINVAL;
+  return false;
+}
+
+
 off_t File::LengthFromPath(const char* name) {
   struct stat st;
   if (TEMP_FAILURE_RETRY(stat(name, &st)) == 0) {
     return st.st_size;
   }
   return -1;
 }
 
 
 time_t File::LastModified(const char* name) {
@@ skipping 114 matching lines @@
       TEMP_FAILURE_RETRY(lstat(file_2, &file_2_info)) == -1) {
     return File::kError;
   }
   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;
 }
 
 #endif  // defined(TARGET_OS_MACOS)