FSA: Reject moves with empty names

move("") rejects with a TypeError, while move(dir, "") succeeds
(by ignoring the second arg). Make this consistent by always rejecting
if there's an invalid name, as specified in
https://wicg.github.io/file-system-access/#valid-file-name

See whatwg/fs#10 (comment)

Bug: 1327741
Change-Id: Ifd8457df05aad7f75007ff5eece6237a09098a94

fs/script-tests/FileSystemFileHandle-move.js

@@ -138,15 +138,15 @@ directory_test(async (t, root) => {
   const dir_src = await root.getDirectoryHandle('dir-src', {create: true});
   const dir_dest = await root.getDirectoryHandle('dir-dest', {create: true});
   const file = await createFileWithContents(t, 'file', 'abc', dir_src);
-  await file.move(dir_dest, '');
+  await promise_rejects_js(t, TypeError, file.move(dir_dest, ''));
 
   assert_array_equals(
       await getSortedDirectoryEntries(root), ['dir-dest/', 'dir-src/']);
-  assert_array_equals(await getSortedDirectoryEntries(dir_src), []);
-  assert_array_equals(await getSortedDirectoryEntries(dir_dest), ['file']);
+  assert_array_equals(await getSortedDirectoryEntries(dir_src), ['file']);
+  assert_array_equals(await getSortedDirectoryEntries(dir_dest), []);
   assert_equals(await getFileContents(file), 'abc');
   assert_equals(await getFileSize(file), 3);
-}, 'move(dir, "") to move a file to a new directory');
+}, 'move(dir, "") to move a file to a new directory fails');
 
 directory_test(async (t, root) => {
   const dir_src = await root.getDirectoryHandle('dir-src', {create: true});
@@ -191,33 +191,6 @@ directory_test(async (t, root) => {
   assert_equals(await getFileContents(handle), 'foo');
 }, 'move(dir) can be called multiple times');
 
-directory_test(async (t, root) => {
-  const dir1 = await root.getDirectoryHandle('dir1', {create: true});
-  const dir2 = await root.getDirectoryHandle('dir2', {create: true});
-  const handle = await createFileWithContents(t, 'file', 'foo', root);
-
-  await handle.move(dir1, "");
-  assert_array_equals(
-      await getSortedDirectoryEntries(root), ['dir1/', 'dir2/']);
-  assert_array_equals(await getSortedDirectoryEntries(dir1), ['file']);
-  assert_array_equals(await getSortedDirectoryEntries(dir2), []);
-  assert_equals(await getFileContents(handle), 'foo');
-
-  await handle.move(dir2, "");
-  assert_array_equals(
-      await getSortedDirectoryEntries(root), ['dir1/', 'dir2/']);
-  assert_array_equals(await getSortedDirectoryEntries(dir1), []);
-  assert_array_equals(await getSortedDirectoryEntries(dir2), ['file']);
-  assert_equals(await getFileContents(handle), 'foo');
-
-  await handle.move(root, "");
-  assert_array_equals(
-      await getSortedDirectoryEntries(root), ['dir1/', 'dir2/', 'file']);
-  assert_array_equals(await getSortedDirectoryEntries(dir1), []);
-  assert_array_equals(await getSortedDirectoryEntries(dir2), []);
-  assert_equals(await getFileContents(handle), 'foo');
-}, 'move(dir, "") can be called multiple times');
-
 directory_test(async (t, root) => {
   const dir1 = await root.getDirectoryHandle('dir1', {create: true});
   const dir2 = await root.getDirectoryHandle('dir2', {create: true});