cidb: eliminate CL status files

This CL eliminates use of CL status files and status counters.

For the CQ, the status counters were used in generating summary text
that included the number of prior failures (and in the past also in
identifying suspects, but this is no longer the case). The counters have
been replaced by counting the number of occurences of KICKED_OUT actions
for the change.

For the pre-CQ, status files were used to coordinate and track state, by
the pre-cq-launcher, the pre-cq-group, and master-paladin. These are
replaced by status transition actions that are recorded to cidb. The
pre-cq status of a given change is the status corresponding to the most
recent pre-cq status action.

 - Rename PRE_CQ_BUILDER_NAME for consistency.
 - Rename GetCLStatus to GetCLPreCQStatus, update all its callers, and
   rewrite it to use the last known pre-CQ action for a change as its
   pre-cq status.
 - Rename UpdateCLStatus to UpdateCLPreCQStatus, update all its callers
   (deleting callers that were CQ-specific), and rewrite it to only
   record a status transition action to cidb.
 - Delete _FindPreviouslyFailedChanges, which was not used anywhere.
 - Do not update a change's pass_count, this was only used when printing
   CL summary links, and not clear why this should ever be nonzero.
 - Delete CLStatusMock, instead use FakeCIDBConnection in unit
   tests and do not mock out the CL status methods.

BUG=chromium:410546
TEST=`git grep PRE_CQ_BUILDER_NAME` -> no results
`git grep GetCLStatus` -> no results
`git grep UpdateCLStatus` -> no results
`git grep _FindPreviouslyFailedChanges` -> no results
New unit tests of GetCLActionCount, UpdateCLPreCQStatus, and
GetCLPreCQStatus.
Existing unit tests fixed and passing.
Remote trybots.
Local trybots.

Change-Id: I91752207782ff7278e0a4ada4388fcf3509b1860
Reviewed-on: https://chromium-review.googlesource.com/221956
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>

1 files changed, 0 insertions, 2 deletions

diff --git a/cbuildbot/stages/report_stages_unittest.py b/cbuildbot/stages/report_stages_unittest.py
index 4da178c00..a9926e849 100755
--- a/cbuildbot/stages/report_stages_unittest.py
+++ b/cbuildbot/stages/report_stages_unittest.py
@@ -112,8 +112,6 @@ class ReportStageTest(generic_stages_unittest.AbstractStageTest):
       self.StartPatcher(mock.patch.object(*cmd, autospec=True))
 
     self.StartPatcher(BuilderRunMock())
-    self.cq = sync_stages_unittest.CLStatusMock()
-    self.StartPatcher(self.cq)
     self.sync_stage = None
 
     # Set up a general purpose cidb mock. Tests with more specific