Factor out common code in PingLoader methods
Factor out common code in PingLoader methods

BUG=none
R=sof

Review URL: https://codereview.chromium.org/1251453005

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@199824 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk