Do not return file descriptor if target is a directory in IsolatedFileSystem

webkit/fileapi/native_file_util.cc

Index: webkit/fileapi/native_file_util.cc
diff --git a/webkit/fileapi/native_file_util.cc b/webkit/fileapi/native_file_util.cc
index ff82e7726be4293a6e1f82b7ccd9032bb2cebca0..e64fa052ecb8832349bfbec33c7d8631b9f9376c 100644
--- a/webkit/fileapi/native_file_util.cc
+++ b/webkit/fileapi/native_file_util.cc
@@ -85,6 +85,8 @@ PlatformFileError NativeFileUtil::CreateOrOpen(
     // If its parent does not exist, should return NOT_FOUND error.
     return base::PLATFORM_FILE_ERROR_NOT_FOUND;
   }
+  if (file_util::DirectoryExists(path))
+    return base::PLATFORM_FILE_ERROR_NOT_A_FILE;
   PlatformFileError error_code = base::PLATFORM_FILE_OK;
   *file_handle = base::CreatePlatformFile(path, file_flags,
                                           created, &error_code);