Expose SkWriteBuffer in component builds

The chromium compositor wants to lean on Skia internal serialization (at
least temporarily, but possibly long term as well) for certain types.
As flattening types requires an SkWriteBuffer, make SkWriteBuffer
have public visibility in component builds.

Change-Id: I635f89bcf816aa376682bd7f7ef46de7d5669e12
Reviewed-on: https://skia-review.googlesource.com/18700
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
1 file changed