Revert "increase Builder's prealloc size after colorspace change"

This reverts commit e53de483930fc76f618da23940a6577d095fd136.

Reason for revert: Key size distribution has changed back.

Original change's description:
> increase Builder's prealloc size after colorspace change
> 
> BUG=skia:
> 
> Change-Id: I003dcbde7d987404ae823df6621e13664cf440a1
> Reviewed-on: https://skia-review.googlesource.com/9523
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=bsalomon@google.com,robertphillips@google.com,brianosman@google.com,reed@google.com

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

Bug: skia:
Change-Id: I506a1ec791e6d99df1836cbf3262747fbfa224a7
Reviewed-on: https://skia-review.googlesource.com/153008
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
5 files changed