GitLab

This reverts commit 1d267524.

Reason for revert: Suespect that this broke the build on Windows.

Original change's description:
> Added access operator to color mixers.
> 
> Added the access operator to the color mixer class, updated existing
> code and tests. Changed AddMixer() to return a mixer by reference.
> 
> Bug: 1887666
> Change-Id: I2ae180f77d73e3ce4567d061b5505d920677c450
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1910521
> Commit-Queue: Peter Kasting <pkasting@chromium.org>
> Reviewed-by: Peter Kasting <pkasting@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#714528}

TBR=pkasting@chromium.org,tluk@chromium.org

Change-Id: I7eae3b7e1824b31adaa04c5e998c883da05eea96
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1887666
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1911709Reviewed-by: James MacLean <wjmaclean@chromium.org>
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714543}