The patch fixes a compilation bug caused from having local variable
names clash with the variables names from a parent scope.

BUG=angleproject:1815

Change-Id: I3d23faaafdea9be503da99512b204d7a50a3b228
Reviewed-on: https://chromium-review.googlesource.com/571000Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>