Allow to pass remount option to Mount method of cros_disks_client.

chromeos/dbus/fake_cros_disks_client.h

Index: chromeos/dbus/fake_cros_disks_client.h
diff --git a/chromeos/dbus/fake_cros_disks_client.h b/chromeos/dbus/fake_cros_disks_client.h
index d12177deaa30605511807ade6667f7332711cc30..ef89b843098e93fc1ad76f6203f752449f193c6c 100644
--- a/chromeos/dbus/fake_cros_disks_client.h
+++ b/chromeos/dbus/fake_cros_disks_client.h
@@ -31,8 +31,10 @@ class CHROMEOS_EXPORT FakeCrosDisksClient : public CrosDisksClient {
              const std::string& source_format,
              const std::string& mount_label,
              MountAccessMode access_mode,
+             RemountOption remount,
              const base::Closure& callback,
              const base::Closure& error_callback) override;
+
   // Deletes the directory created in Mount().
   void Unmount(const std::string& device_path,
                UnmountOptions options,