Update Gaia API documents for #0dd660f876f110185f15877332c6e00ed7c761bb
    Revert "Merge pull request #14138 from malini/mixin"

This reverts commit 091161997bebfc0c2d053339b1c9891c57216920, reversing
changes made to 50c75716ce9740ac1443e02140ae85b4885d47c5.