Change access mode of disk devices when mounting based on config.

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

Index: chrome/browser/chromeos/extensions/file_manager/private_api_mount.cc
diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_mount.cc b/chrome/browser/chromeos/extensions/file_manager/private_api_mount.cc
index 2943bbff1f4aa3af1d072578fcf78287cdcfd73e..9bb59027cd07e4690dd0d13ba13ba1e8a83c3714 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_mount.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_mount.cc
@@ -16,9 +16,11 @@
 #include "chrome/browser/chromeos/file_manager/volume_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/file_manager_private.h"
+#include "chrome/common/pref_names.h"
 #include "chromeos/disks/disk_mount_manager.h"
 #include "components/drive/chromeos/file_system_interface.h"
 #include "components/drive/event_logger.h"
+#include "components/prefs/pref_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "google_apis/drive/task_util.h"
 #include "ui/shell_dialogs/selected_file_info.h"
@@ -160,11 +162,15 @@ void FileManagerPrivateAddMountFunction::RunAfterMarkCacheFileAsMounted(
 
   // MountPath() takes a std::string.
   DiskMountManager* disk_mount_manager = DiskMountManager::GetInstance();
+  bool read_only =
+      GetProfile()->GetPrefs()->GetBoolean(prefs::kExternalStorageReadOnly);
+  chromeos::MountAccessMode access_mode =
+      read_only ? chromeos::MOUNT_ACCESS_MODE_READ_ONLY
+                : chromeos::MOUNT_ACCESS_MODE_READ_WRITE;
   disk_mount_manager->MountPath(
       file_path.AsUTF8Unsafe(),
       base::FilePath(display_name.Extension()).AsUTF8Unsafe(),
-      display_name.AsUTF8Unsafe(),
-      chromeos::MOUNT_TYPE_ARCHIVE);
+      display_name.AsUTF8Unsafe(), chromeos::MOUNT_TYPE_ARCHIVE, access_mode);

[fukino, 2016/08/03 07:18:19]

Should we specify access mode for mounted archive files?

[yamaguchi, 2016/08/03 10:22:14]

Done.
Mounted archives are treated as read-only by itself now.

 }
 
 bool FileManagerPrivateRemoveMountFunction::RunAsync() {