Clean up direct access of ShaderVariable::arraySize This change is pure refactoring. It's intended to help with adding support for arrays of arrays. BUG=angleproject:2125 TEST=angle_unittests Change-Id: I82881a98c3c476fd6666a551ce6be255ae0de4cf Reviewed-on: https://chromium-review.googlesource.com/733127 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>