* Include the correct header right in the SSE check in platform.h.
* Don't use separate SSE versions of the load functions, have them use
  SSE automatically.

BUG=612205

Change-Id: I70f9a5513e144db4d16c1f3ad922debeb6c50268
Reviewed-on: https://chromium-review.googlesource.com/358108Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>