--- a/testing/web-platform/tests/native-file-system/FileSystemBaseHandle-remove.tentative.https.window.js
+++ b/testing/web-platform/tests/native-file-system/FileSystemBaseHandle-remove.tentative.https.window.js
@@ -39,38 +39,38 @@ promise_test(async t => {
     await promise_rejects(t, 'InvalidModificationError', root.removeEntry('dir-to-remove'));
     assert_array_equals(await getSortedDirectoryEntries(root), ['dir-to-remove/']);
     assert_array_equals(await getSortedDirectoryEntries(dir), ['file-in-dir']);
 }, 'removeEntry() on a non-empty directory should fail');
 
 promise_test(async t => {
     const root = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
     const dir = await createDirectory(t, 'dir', root);
-    await promise_rejects(t, 'NotFoundError', dir.removeEntry(""));
+    await promise_rejects(t, new TypeError(), dir.removeEntry(""));
 }, 'removeEntry() with empty name should fail');
 
 promise_test(async t => {
     const root = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
     const dir = await createDirectory(t, 'dir', root);
-    await promise_rejects(t, 'SecurityError', dir.removeEntry(kCurrentDirectory));
+    await promise_rejects(t, new TypeError(), dir.removeEntry(kCurrentDirectory));
 }, `removeEntry() with "${kCurrentDirectory}" name should fail`);
 
 promise_test(async t => {
     const root = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
     const dir = await createDirectory(t, 'dir', root);
-    await promise_rejects(t, 'SecurityError', dir.removeEntry(kParentDirectory));
+    await promise_rejects(t, new TypeError(), dir.removeEntry(kParentDirectory));
 }, `removeEntry() with "${kParentDirectory}" name should fail`);
 
 promise_test(async t => {
     const root = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
 
     const dir_name = 'dir-name';
     const dir = await createDirectory(t, dir_name, root);
 
     const file_name = 'file-name';
     await createEmptyFile(t, file_name, dir);
 
     for (let i = 0; i < kPathSeparators.length; ++i) {
         const path_with_separator = `${dir_name}${kPathSeparators[i]}${file_name}`;
-        await promise_rejects(t, 'SecurityError', root.removeEntry(path_with_separator),
+        await promise_rejects(t, new TypeError(), root.removeEntry(path_with_separator),
             `removeEntry() must reject names containing "${kPathSeparators[i]}"`);
     }
 }, 'removeEntry() with a path separator should fail.');

--- a/testing/web-platform/tests/native-file-system/FileSystemDirectoryHandle-getDirectory.tentative.https.window.js
+++ b/testing/web-platform/tests/native-file-system/FileSystemDirectoryHandle-getDirectory.tentative.https.window.js
@@ -53,54 +53,54 @@ promise_test(async t => {
 
     await promise_rejects(t, 'TypeMismatchError', root.getDirectory('file-name'));
     await promise_rejects(t, 'TypeMismatchError', root.getDirectory('file-name', { create: false }));
     await promise_rejects(t, 'TypeMismatchError', root.getDirectory('file-name', { create: true }));
 }, 'getDirectory() when a file already exists with the same name');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
-    await promise_rejects(t, 'NotFoundError', dir.getDirectory("", { create: true }));
-    await promise_rejects(t, 'NotFoundError', dir.getDirectory("", { create: false }));
+    await promise_rejects(t, new TypeError(), dir.getDirectory("", { create: true }));
+    await promise_rejects(t, new TypeError(), dir.getDirectory("", { create: false }));
 }, 'getDirectory() with empty name');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
-    await promise_rejects(t, 'SecurityError', dir.getDirectory(kCurrentDirectory));
-    await promise_rejects(t, 'SecurityError', dir.getDirectory(kCurrentDirectory, { create: true }));
+    await promise_rejects(t, new TypeError(), dir.getDirectory(kCurrentDirectory));
+    await promise_rejects(t, new TypeError(), dir.getDirectory(kCurrentDirectory, { create: true }));
 }, `getDirectory() with "${kCurrentDirectory}" name`);
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
     const subdir = await createDirectory(t, 'subdir-name', /*parent=*/dir);
 
-    await promise_rejects(t, 'SecurityError', subdir.getDirectory(kParentDirectory));
-    await promise_rejects(t, 'SecurityError', subdir.getDirectory(kParentDirectory, { create: true }));
+    await promise_rejects(t, new TypeError(), subdir.getDirectory(kParentDirectory));
+    await promise_rejects(t, new TypeError(), subdir.getDirectory(kParentDirectory, { create: true }));
 }, `getDirectory() with "${kParentDirectory}" name`);
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
 
     const first_subdir_name = 'first-subdir-name';
     const first_subdir = await createDirectory(t, first_subdir_name, /*parent=*/dir);
 
     const second_subdir_name = 'second-subdir-name';
     const second_subdir = await createDirectory(t, second_subdir_name, /*parent=*/first_subdir);
 
     for (let i = 0; i < kPathSeparators.length; ++i) {
         const path_with_separator = `${first_subdir_name}${kPathSeparators[i]}${second_subdir_name}`;
-        await promise_rejects(t, 'SecurityError', dir.getDirectory(path_with_separator),
+        await promise_rejects(t, new TypeError(), dir.getDirectory(path_with_separator),
             `getDirectory() must reject names containing "${kPathSeparators[i]}"`);
     }
 }, 'getDirectory(create=false) with a path separator when the directory exists');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
 
     const subdir_name = 'subdir-name';
     const subdir = await createDirectory(t, subdir_name, /*parent=*/dir);
 
     for (let i = 0; i < kPathSeparators.length; ++i) {
         const path_with_separator = `${subdir_name}${kPathSeparators[i]}file_name`;
-        await promise_rejects(t, 'SecurityError', dir.getDirectory(path_with_separator, { create: true }),
+        await promise_rejects(t, new TypeError(), dir.getDirectory(path_with_separator, { create: true }),
             `getDirectory(true) must reject names containing "${kPathSeparators[i]}"`);
     }
 }, 'getDirectory(create=true) with a path separator');

--- a/testing/web-platform/tests/native-file-system/FileSystemDirectoryHandle-getFile.tentative.https.window.js
+++ b/testing/web-platform/tests/native-file-system/FileSystemDirectoryHandle-getFile.tentative.https.window.js
@@ -58,54 +58,54 @@ promise_test(async t => {
     const dir_handle = await dir.getDirectory('dir-name', { create: true });
     t.add_cleanup(() => dir.removeEntry('dir-name', { recursive: true }));
 
     await promise_rejects(t, 'TypeMismatchError', dir.getFile('dir-name', { create: true }));
 }, 'getFile(create=true) when a directory already exists with the same name');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
-    await promise_rejects(t, 'NotFoundError', dir.getFile("", { create: true }));
-    await promise_rejects(t, 'NotFoundError', dir.getFile("", { create: false }));
+    await promise_rejects(t, new TypeError(), dir.getFile("", { create: true }));
+    await promise_rejects(t, new TypeError(), dir.getFile("", { create: false }));
 }, 'getFile() with empty name');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
-    await promise_rejects(t, 'SecurityError', dir.getFile(kCurrentDirectory));
-    await promise_rejects(t, 'SecurityError', dir.getFile(kCurrentDirectory, { create: true }));
+    await promise_rejects(t, new TypeError(), dir.getFile(kCurrentDirectory));
+    await promise_rejects(t, new TypeError(), dir.getFile(kCurrentDirectory, { create: true }));
 }, `getFile() with "${kCurrentDirectory}" name`);
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
     const subdir = await createDirectory(t, 'subdir-name', /*parent=*/dir);
 
-    await promise_rejects(t, 'SecurityError', subdir.getFile(kParentDirectory));
-    await promise_rejects(t, 'SecurityError', subdir.getFile(kParentDirectory, { create: true }));
+    await promise_rejects(t, new TypeError(), subdir.getFile(kParentDirectory));
+    await promise_rejects(t, new TypeError(), subdir.getFile(kParentDirectory, { create: true }));
 }, `getFile() with "${kParentDirectory}" name`);
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
 
     const subdir_name = 'subdir-name';
     const subdir = await createDirectory(t, subdir_name, /*parent=*/dir);
 
     const file_name = 'file-name';
     await createEmptyFile(t, file_name, /*parent=*/subdir);
 
     for (let i = 0; i < kPathSeparators.length; ++i) {
         const path_with_separator = `${subdir_name}${kPathSeparators[i]}${file_name}`;
-        await promise_rejects(t, 'SecurityError', dir.getFile(path_with_separator),
+        await promise_rejects(t, new TypeError(), dir.getFile(path_with_separator),
             `getFile() must reject names containing "${kPathSeparators[i]}"`);
     }
 }, 'getFile(create=false) with a path separator when the file exists.');
 
 promise_test(async t => {
     const dir = await FileSystemDirectoryHandle.getSystemDirectory({ type: 'sandbox' });
 
     const subdir_name = 'subdir-name';
     const subdir = await createDirectory(t, subdir_name, /*parent=*/dir);
 
     for (let i = 0; i < kPathSeparators.length; ++i) {
         const path_with_separator = `${subdir_name}${kPathSeparators[i]}file_name`;
-        await promise_rejects(t, 'SecurityError', dir.getFile(path_with_separator, { create: true }),
+        await promise_rejects(t, new TypeError(), dir.getFile(path_with_separator, { create: true }),
             `getFile(true) must reject names containing "${kPathSeparators[i]}"`);
     }
 }, 'getFile(create=true) with a path separator');