Reland "Refactor update_client deps."

This is a reland of 46935a5d3a85362f574f967780348f4c5c8dad57

Original change's description:
> Refactor update_client deps.
> 
> This reduces the build artifacts necessary to build chrome/updater from
> 5k to 1.7k.
> 
> Change-Id: I7332c69a5f564a08786d7e21e5891448feca8f11
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1557988
> Commit-Queue: Joshua Pawlicki <[email protected]>
> Reviewed-by: Sorin Jianu <[email protected]>
> Reviewed-by: Sylvain Defresne <[email protected]>
> Reviewed-by: Nico Weber <[email protected]>
> Reviewed-by: Devlin <[email protected]>
> Auto-Submit: Joshua Pawlicki <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#649098}

Change-Id: I6c50876963ceea92eb1ea05488797c6a06efbb12
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1559874
Auto-Submit: Joshua Pawlicki <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Reviewed-by: Devlin <[email protected]>
Reviewed-by: Sylvain Defresne <[email protected]>
Commit-Queue: Joshua Pawlicki <[email protected]>
Cr-Commit-Position: refs/heads/master@{#649483}
8 files changed