Revert "Revert "Revert "Revert "Revert "Make threaded proxy generation MDB-friendly, and defer instantiation"""""

This reverts commit fdd2cb52b781dd68f515a1eb9fe6d054a0ebc226.

Reason for revert: ANGLE gold failures

Original change's description:
> Revert "Revert "Revert "Revert "Make threaded proxy generation MDB-friendly, and defer instantiation""""
> 
> This reverts commit 9f8d4d36b514ffe3cc3a4a48900e3dc1fecb2a96.
> 
> Bug: skia:
> Change-Id: I8d7c1df24d8b13b94404f3d9ba69a1ab55ee00c0
> Reviewed-on: https://skia-review.googlesource.com/52920
> Commit-Queue: Brian Osman <brianosman@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=egdaniel@google.com,robertphillips@google.com,brianosman@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: skia:
Change-Id: Ie461de167fbd37323cabd4adf064f99204ba4878
Reviewed-on: https://skia-review.googlesource.com/53801
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
12 files changed