Add zakerinasab@ to the OWNERS of core/imagebitmap

TBR=junov@chromium.org

Bug: None
Change-Id: Ib34c35f73778b71cea041b81dcf94ca413f0e13a
Reviewed-on: https://chromium-review.googlesource.com/887962Reviewed-by: Xida Chen <xidachen@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532054}

third_party/WebKit/Source/core/imagebitmap/OWNERS

-xidachen@chromium.org
 junov@chromium.org
+zakerinasab@chromium.org
 
 # TEAM: paint-dev@chromium.org
 # COMPONENT: Blink>Canvas