We can't use this method on OSX due to missing c++11 STL support.
Instead use a helper function to replace it.

BUG=angle:773

Change-Id: Iddcd2705792217e6356f51e4bb9dce248d7c3be2
Reviewed-on: https://chromium-review.googlesource.com/238447Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>