mozilla-services/android-sync — comment on commit db2de0f8434be941663bbf5857bfbe7467200499
File: src/main/java/org/mozilla/gecko/sync/stage/SyncClientsEngineStage.java line 103
By rnewman:

This is in the "HTTP request is done, and we've parsed the whole body" spot — no better place. The HTTP request is done. You're right that it does delay re-upload, but then if we fall over processing the command, do we want to reupload?

(And X-If-Unmodified-Since resolves that problem, anyway.)