Take a look at this Application Cache Manifest file generated by Google Drive:
CACHE MANIFEST
# 0 145
# 0
CACHE:
# 41576c4d6173fb52cebef31e00ecd0b9386d2dd4
/static/doclist/client/js/3137775926-frame_bin.js
# e1c0003f2b2931468ae838ab49c67a03fa92e9e3
/static/doclist/client/js/1541866789-docs_offline_iframe_api_bin.js
# 62f8e33bd13b84db3f1fb605b84caddd7eb3ba71
/static/doclist/client/js/3702789471-event_bus_worker_bin.js
# c2f83bae24c17992c10113b37cabf87aedb7ed93
/static/doclist/client/js/3894149994-offline_tasks_worker_bin.js
FALLBACK:
CHROMIUM-INTERCEPT:
/offline/extension/frame?ouid return /offline/extension/frame?ouid&releaseData=683748092
/offline/extension/frame?ouid=u974423e25325d962 return /offline/extension/frame?ouid=u974423e25325d962&releaseData=683748092
/offline/iframeapi?ouid=u974423e25325d962 return /offline/iframeapi?ouid=u974423e25325d962&releaseData=683748092
/offline/eventbusworker.js?ouid=u974423e25325d962 return /offline/eventbusworker.js?ouid=u974423e25325d962&releaseData=683748092
/offline/synctaskworker.js?ouid=u974423e25325d962 return /offline/synctaskworker.js?ouid=u974423e25325d962&releaseData=683748092
/offline/flags?ouid=u974423e25325d962 return /offline/flags?ouid=u974423e25325d962&releaseData=683748092
/offline/taskiframe?ouid=u974423e25325d962 return /offline/taskiframe?ouid=u974423e25325d962&releaseData=683748092
NETWORK:
https://ssl.gstatic.com/docs/common/cleardot.gif
/bind
/test
*
Fairly boring until you get to the section, CHROMIUM-INTERCEPT:. I couldn't find any documentation about this section, only a few Chromium Bugs mentioning it by name (link), but nothing directly stating what it does.
What is CHROMIUM-INTERCEPT? Is it a proprietary thing Google added to their AppCache implementation to make their lives easier? Are non-Google products allowed to use it? What does it do?
