Revert "remove guard for computeByteSize api"

This reverts commit d72747c5c3b3aaaa9e5957242bd478980cac942e.

Reason for revert: broke //htmlrender/webkit_headless/engine/testing:platform_web_unittests

Original change's description:
> remove guard for computeByteSize api
> 
> Bug: skia:
> Change-Id: I5c66a7c79c4e71ec82194e8d37de04a516028665
> Reviewed-on: https://skia-review.googlesource.com/56402
> Reviewed-by: Mike Reed <reed@google.com>

TBR=reed@google.com,reed@chromium.org

Change-Id: If721607583204df9f32e54a041ecc8b34ad1a749
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/56321
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed