The generic alignment and conversion test to check for the possibility of using
direct storage is relatively expensive. Float types can be tested more quickly.

BUG=angle:613

Change-Id: I5ab008ce82c8b652f0392c20a80a5b198b2437a5
Reviewed-on: https://chromium-review.googlesource.com/197721Tested-by: Nicolas Capens <nicolascapens@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>