Supersize: Add more OWNERS

NOTRY=true

Bug: None
Change-Id: I40ae8bda58079de746b2947dca0b41b70afb2d9a
Reviewed-on: https://chromium-review.googlesource.com/941921Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539950}

tools/binary_size/OWNERS

 agrieve@chromium.org
 estevenson@chromium.org
+huangs@chromium.org
+wnwen@chromium.org
 
 # binary-size@chromium.org
 # COMPONENT: Tools