Remove dontRemoveInvariantForFragmentInput WA Previously removed supporting code for the workaround "dontRemoveInvariantForFragmentInput" but missed this declaration. Bug: angleproject:3285 Change-Id: Ia23b424f2ccbdfe98b7cec79e4290b3621e44238 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1601945 Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Tobin Ehlis <tobine@google.com>