If data is non-null and size is zero, the memory buffer may have a NULL
pointer.

BUG=angle:765

Change-Id: I4cb8f54ec85fea886e37ee2d4469d26e651a916b
Reviewed-on: https://chromium-review.googlesource.com/220801Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>