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This is class is unused following crrev.com/c/2470877. This CL removes,
together with the Commit*::CleanUp() methods which are now unnecessary.

Fixed: 1137896
Change-Id: I75a7e4b64da970cc8f84966c57d1225693737103
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2470528Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/master@{#817576}