Use SkTArray for mailbox polling

The mailbox uses SkTArray internally, so swapping is optimal when dest
has no preallocated storage.

Change-Id: Ic295f3707d07c97b1881e775cac3a23a6b2fef71
Reviewed-on: https://skia-review.googlesource.com/9641
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed