Reland "Merge GrContext::init into GrDirectContext ..."

This reverts commit e9b9c3bd7f1900264f18ffe9b3d2b9ff41a7f5cd.

Reason for revert: Fixed MSVC

Original change's description:
> Revert "Merge GrContext::init into GrDirectContext ..."
>
> This reverts commit 48d8724097d0b108259c2aef7df8ed1aa08bd574.
>
> Reason for revert: Breaking MSVC bots
>
> Original change's description:
> > Merge GrContext::init into GrDirectContext ...
> >
> > And minor cleanups associated with the initialization of these classes.
> >
> > Change-Id: Ida0372d0b1a0b8bf5b309814de5418e47ea34fdb
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/324122
> > Commit-Queue: Adlai Holler <adlai@google.com>
> > Reviewed-by: Robert Phillips <robertphillips@google.com>
> > Auto-Submit: Adlai Holler <adlai@google.com>
>
> TBR=robertphillips@google.com,adlai@google.com
>
> Change-Id: I00b2ddaeaef53e3fe05a338c88158cf235f325c4
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/324132
> Reviewed-by: Jim Van Verth <jvanverth@google.com>
> Commit-Queue: Jim Van Verth <jvanverth@google.com>

TBR=jvanverth@google.com,robertphillips@google.com,adlai@google.com


Change-Id: I88bac7cd3aab070460671e82cbd924fbb42a2740
Cq-Include-Trybots: luci.skia.skia.primary:Build-Win-MSVC-x86_64-Release-Shared,Build-Win-Clang-x86_64-Release-Shared
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/324616
Commit-Queue: Adlai Holler <adlai@google.com>
Reviewed-by: Adlai Holler <adlai@google.com>
5 files changed