[test] Continuously run test-runner tests

The tests already run on upload and commit. This makes them run on the
corresponding continuous tester.

NOTRY=true
TBR=sergiyb@chromium.org

Bug: v8:6917
Change-Id: I7dedd482ea54f0879854055c97b27f825f06d6e2
Reviewed-on: https://chromium-review.googlesource.com/846807Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50343}

tools/presubmit.py

@@ -554,9 +554,15 @@ def CheckDeps(workspace):
 
 
 def PyTests(workspace):
-  test_scripts = join(workspace, 'tools', 'release', 'test_scripts.py')
-  return subprocess.call(
-      [sys.executable, test_scripts], stdout=subprocess.PIPE) == 0
+  result = True
+  for script in [
+      join(workspace, 'tools', 'release', 'test_scripts.py'),
+      join(workspace, 'tools', 'unittests', 'run_tests_test.py'),
+    ]:
+    print 'Running ' + script
+    result &= subprocess.call(
+        [sys.executable, script], stdout=subprocess.PIPE) == 0
+  return result
 
 
 def GetOptions():
@@ -573,8 +579,8 @@ def Main():
   success = True
   print "Running checkdeps..."
   success &= CheckDeps(workspace)
-  print "Running C++ lint check..."
   if not options.no_lint:
+    print "Running C++ lint check..."
     success &= CppLintProcessor().RunOnPath(workspace)
   print "Running copyright header, trailing whitespaces and " \
         "two empty lines between declarations check..."