This reverts commit 812ac228.

Reason for revert: The fix was not sufficient to solve the git cl
format difference between 'git cl format' and 'git cl format --full'.
Looks like we'll need a different solution.

Original change's description:
> git-cl: Add diff lines of context setting.
> 
> Clients using some Clang-Format options can run into bugs when using
> 0 lines of context. AlignConsecutiveAssignments in particular is picky
> and behaves differently with 0 lines of context.
> 
> This behaviour lead to 'git cl format' behaving differently from
> 'git cl format --full'. That could also break presubmit format checks.
> Using >0 lines of context for 'git diff' fixes the inconsistency.
> 
> Add a setting 'DIFF_LINES_OF_CONTEXT' that can be controlled via
> codereview.settings. Defaults to zero to preserve the old behaviour.
> The setting allows the client to control the number of lines of context
> to use when running 'git cl format'.
> 
> Bug: angleproject:4003
> Change-Id: Ied2ebf23df4c41ba19bfbd5b8ddf526b56a20b31
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1864309
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
> Commit-Queue: Jamie Madill <jmadill@chromium.org>

TBR=agable@chromium.org,ehmaldonado@chromium.org,jmadill@chromium.org

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

Bug: angleproject:4003
Change-Id: Ib6b70969509a1e5446922d488f11d13a0c59c536
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1877003Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>