Remove a couple of unused methods from sel_ldr_launcher_base.

Remove a couple of unused methods from SelLdrLauncherBase.

(*) StartModuleAndSetupAppChannel -- StartModule
    and SetupAppChannel can just be called separately
    (though only called by sel_universal and the
    sel_main_chrome_test). They aren't used by Chrome.
(*) SetupCommandAndLoad -- SetupCommand is used by chrome,
    and LoadModule is only used by sel_universal.
    Could have been called separately.
(*) Wrap(), WrapCleanup(), secure_socket_addr() aren't used.
(*) ConnectBootstrapSocket and RetrieveSockAddr are used internally
    so make them private.
(*) Add "private" to make some lint checks happy with the
    DISALLOW_COPY_AND_ASSIGN.

BUG=none
R=mseaborn@chromium.org

Committed: https://chromium.googlesource.com/native_client/src/native_client/+/9e6f51021bdf1a395b072bcea94d55787511d301

[jvoung (off chromium), 2015-04-14 23:55:28]

jvoung@chromium.org changed reviewers:
+ mseaborn@chromium.org, phosek@chromium.org

[Mark Seaborn, 2015-04-15 02:42:28]

LGTM

[jvoung (off chromium), 2015-04-15 18:45:00]

Committed patchset #1 (id:1) manually as
9e6f51021bdf1a395b072bcea94d55787511d301 (presubmit successful).