Add an easy way to preview ArrayBuffer as a typed array. This change
will always allow previewing ArrayBuffer instances as Uint8Array and
Int8Array. ArrayBuffer instances that have even length will allow
Int16Array preview and ArrayBuffers that have length divisible by 4 will
allow Int32Array previews.

Bug: 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I07440147cc9e83c8a987f9316bd8d1b936db2717
Reviewed-on: https://chromium-review.googlesource.com/842472
Commit-Queue: Eugene Ostroukhov <eostroukhov@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50315}