Revert "[DL]: Implement updateAndCommit()."

This reverts commit 33c85095df347a7de7ec8f80786161a716ad82cc.

Reason for revert: Newly added tests fail on MSAN https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/WebKit%20Linux%20Trusty%20MSAN/12380

Original change's description:
> [DL]: Implement updateAndCommit().
> 
> This patch adds updateAndCommit() which updates the subtree cooperatively
> and then commits.
> 
> R=​chrishtr@chromium.org
> 
> Bug: 882663
> Change-Id: I14b906ff1ccf2ed57df082bfe883bb5d4c6e9ac3
> Reviewed-on: https://chromium-review.googlesource.com/c/1422867
> Commit-Queue: vmpstr <vmpstr@chromium.org>
> Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#626242}

TBR=vmpstr@chromium.org,chrishtr@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 882663
Change-Id: Ib9ad778b10923a061b420d2c55475bcae82926f8
Reviewed-on: https://chromium-review.googlesource.com/c/1439621
Reviewed-by: Kevin McNee <mcnee@chromium.org>
Commit-Queue: Kevin McNee <mcnee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626572}
19 files changed