Allow to create read only testing volumes.

chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc

Index: chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
diff --git a/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc b/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
index be00fc6d8d030e8aa283cd6ee15149c5da56ad96..444eee418ada46bdd9c2b76628ccd5dd5da58e14 100644
--- a/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
@@ -424,9 +424,9 @@ IN_PROC_BROWSER_TEST_F(FileManagerPrivateApiTest, ContentChecksum) {
                       kLocalMountPointName, storage::kFileSystemTypeNativeLocal,
                       storage::FileSystemMountOption(), mount_point_dir));
   file_manager::VolumeManager::Get(browser()->profile())
-      ->AddVolumeInfoForTesting(mount_point_dir,
-                                file_manager::VOLUME_TYPE_TESTING,
-                                chromeos::DEVICE_TYPE_UNKNOWN);
+      ->AddVolumeInfoForTesting(
+          mount_point_dir, file_manager::VOLUME_TYPE_TESTING,
+          chromeos::DEVICE_TYPE_UNKNOWN, false /* read_only */);
 
   ASSERT_TRUE(RunComponentExtensionTest("file_browser/content_checksum_test"));
 }