Revert of increase small allocator limit to encompass compose shader (patchset #1 id:1 of https://codereview.chromium.org/2234423005/ )

Reason for revert:
Increase in stack broke Google3

Original issue's description:
> increase small allocator limit to encompass compose shader
>
> R=reed@google.com
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2234423005
>
> Committed: https://skia.googlesource.com/skia/+/8c200694f8eec5f623b3934b85c31dbb382be12c

TBR=reed@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2244293002

src/core/SkImagePriv.h

@@ -18,7 +18,7 @@ enum SkCopyPixelsMode {
     kNever_SkCopyPixelsMode,      //!< never copy src pixels (even if they are marked mutable)
 };
 
-enum {kSkBlitterContextSize = 5300};  // minimum required for compose shader blitter
+enum {kSkBlitterContextSize = 3332};
 
 // Commonly used allocator. It currently is only used to allocate up to 3 objects. The total
 // bytes requested is calculated using one of our large shaders, its context size plus the size of