Revert "Fission GrAtlasGlyphCache in two"

This reverts commit acf17904d6286f2a63a5d895541804d0ea1be646.

Reason for revert: Chrome

Original change's description:
> Fission GrAtlasGlyphCache in two
> 
> This CL splits the old GrAtlasGlyphCache into a GrAtlasGlyphCache and an GrAtlasManager.
> 
> The GrAtlasManager itself is split into a rather limited base class (GrRestrictedAtlasManager)
> and the all powerful GrAtlasManager. The GrRestrictedAtlasManager is available at op creation
> time and provides access to the proxies backing the atlases. The full GrAtlasManager is
> only available at flush time and allows instantiation of the proxies and uploading to them.
> 
> In the DDL world all of the DDL Contexts will receive a GrRestrictedAtlasManager-version of the
> GrAtlasManager in the main thread. This future atlas manager will have had all of its
> GrDrawOpAtlases created (but not instantiated) so there should be no race conditions.
> 
> Change-Id: I9967d3a4116af50128f390c5039a712b8cd4db08
> Reviewed-on: https://skia-review.googlesource.com/108001
> Commit-Queue: Robert Phillips <robertphillips@google.com>
> Reviewed-by: Jim Van Verth <jvanverth@google.com>

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

Change-Id: I7c760ea1a9f041a310b96d552aa1497ee5902cd8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/111040
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
27 files changed