Expose error codes in the CrxUpdateItem.

This allows the clients of UpdateClient inspect the error codes when
an update is complete.

Bug: 843657

Change-Id: I667a58a2723846cdcc4070fc9b103419ea4859d1
Reviewed-on: https://chromium-review.googlesource.com/1060586
Reviewed-by: Joshua Pawlicki <[email protected]>
Commit-Queue: Sorin Jianu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#559256}
6 files changed