Revert "Separate creation time & flush time behavior in GrDrawOpAtlas"

This reverts commit 056c1a821afcfbe606615ad1a7d1b554549d0846.

Reason for revert: GM issues

Original change's description:
> Separate creation time & flush time behavior in GrDrawOpAtlas
> 
> This CL clarifies what is going on in the GrDrawOpAtlas and GrAtlasGlyphCache.
> 
> For the GrDrawOpAtlas:
>   At creation time all the allowed pages are created (with their backing GrTextureProxies) but they aren't instantiated.
> 
>   The GrDrawOpAtlas::instantiate call is called in preFlushCB and allocates any pages known to be needed at the start of flush
> 
>   GrDrawOpAtlas::addToAtlas is called at flush time and, if a new page is activated, will instantiated it at that time.
> 
>   During compaction, an unused page will be deInstantiated but its Plots and backing GrTextureProxy will remain alive.
> 
> The GrAtlasGlyphCache reflects the changes to the GrDrawOpAtlas
>   It now carries a GrProxyProvider for when it needs to create an atlas
>   It passes in a GrResourceProvider* at flush time to allow instantiation.
> 
>   It does not, yet, allocate that GrDrawOpAtlases it might ever require.
> 
> Change-Id: I54909b7a3ba4bec2db5f1218f6a2a3a1636f66d6
> Reviewed-on: https://skia-review.googlesource.com/108520
> 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: I36eafe46209380f533aa84e831d1c9d18844b6be
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/109280
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
16 files changed