Deep shortcuts now supports icon cache.
When workspace is being loaded, we will now attempt to load deep
shortcuts from memcache/db.
The icon for deep shortcuts loaded in the workspace is saved to
memcache/db after the workspace is loaded.
Bug: 140242324
Change-Id: I49da8319ad203476fe1e45683e2848dbde3473f2
Pinyao Ting
Sunny Goyal