Added define to enable/disable uniform precision validation for shaders. This feature was requested by developers to allow non-conformant shaders to be used which contain mismatched precisions. Change-Id: I57899efe064f7ffed1c0e43a508930ac70f6aa03 Reviewed-on: https://chromium-review.googlesource.com/277340 Tested-by: Cooper Partin <coopp@microsoft.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>