checkpoint

Change-Id: Ic24bf3d2260a1159b2e9456f6a110f30e2542de4
optionally use background task

Change-Id: I8f0110f1e6fa0be0d8b51c4bac9210005e54890d
oops

Change-Id: Ic496b9bec33943aaedcdffad3b859fd5f2ab0c48
More learnings

Change-Id: I10dbad547cb7a23560b90daf1665d460c0e18a27
More findings (S3 128kb bug)

Change-Id: I43c28764d2f69c174db586188430fbd54094c0bc
*innocent whistle*

Change-Id: If81346e2c381c2ed6459e934525479d34ad67d54