report_stages: do not abort hwtest suites from wrong branch

It's rude to go around aborting hwtest suites from other branches. Don't
do that.

BUG=chromium:639211
TEST=None

Change-Id: I2c0eb739388240e0e57b9c2a63beb876d71140ec
Previous-Reviewed-on: https://chromium-review.googlesource.com/374721
(cherry picked from commit 4277fb7b2348187ab27192209210ce8ce115ffcb)
Reviewed-on: https://chromium-review.googlesource.com/375039
Tested-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
diff --git a/cbuildbot/stages/report_stages.py b/cbuildbot/stages/report_stages.py
index 3fb8ebe..3a78f4c 100644
--- a/cbuildbot/stages/report_stages.py
+++ b/cbuildbot/stages/report_stages.py
@@ -275,7 +275,7 @@
   written at this time rather than in ReportStage.
   """
 
-  def _AbortPreviousHWTestSuites(self):
+  def _AbortPreviousHWTestSuites(self, milestone):
     """Abort any outstanding synchronous hwtest suites from this builder."""
     # Only try to clean up previous HWTests if this is really running on one of
     # our builders in a non-trybot build.
@@ -285,6 +285,7 @@
     build_id, db = self._run.GetCIDBHandle()
     if db:
       builds = db.GetBuildHistory(self._run.config.name, 2,
+                                  milestone_version=milestone,
                                   ignore_build_id=build_id)
       for build in builds:
         old_version = build['full_version']
@@ -396,7 +397,7 @@
     # Abort previous hw test suites. This happens after reexecution as it
     # requires chromite/third_party/swarming.client, which is not available
     # untill after reexecution.
-    self._AbortPreviousHWTestSuites()
+    self._AbortPreviousHWTestSuites(version['milestone'])
 
 
 class ConfigDumpStage(generic_stages.BuilderStage):