Don't set dirty bits for attribs that are out of range. PrivateState::setAllDirtyBits sets all bits in mDirtyCurrentValues. When the context has fewer max attibutes than MAX_VERTEX_ATTRIBS, this can cause out-of-bounds access to PrivateState::mVertexAttribCurrentValues if the dirty bits are iterated over without range validation. Bug: chromium:1496378 Change-Id: I65481c432263a6e353a9361bba741b97dc5e20b1 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5008034 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>