test: runner should return 0 on flaky tests

Make the test runner return a 0 exit code when only
flaky tests fail and --flaky-tests=dontcare is specified.

Reviewed-By: Julien Gilli <julien.gilli@joyent.com>
PR-URL: #25653

tools/test.py

@@ -68,7 +68,9 @@ def __init__(self, cases, flaky_tests_mode):
     self.remaining = len(cases)
     self.total = len(cases)
     self.failed = [ ]
+    self.flaky_failed = [ ]
     self.crashed = 0
+    self.flaky_crashed = 0
     self.terminate = False
     self.lock = threading.Lock()
 
@@ -129,9 +131,14 @@ def RunSingle(self):
         return
       self.lock.acquire()
       if output.UnexpectedOutput():
-        self.failed.append(output)
-        if output.HasCrashed():
-          self.crashed += 1
+        if FLAKY in output.test.outcomes and self.flaky_tests_mode == "dontcare":
+          self.flaky_failed.append(output)
+          if output.HasCrashed():
+            self.flaky_crashed += 1
+        else:
+          self.failed.append(output)
+          if output.HasCrashed():
+            self.crashed += 1
       else:
         self.succeeded += 1
       self.remaining -= 1