Add test event marking a test as explicitly eligible for rerun if it is marked flakey.

This will be used in a future change to support rerunning flakey tests
that hit a test result isue in a low-load, single worker test runner phase.

This is implemented as an additive-style event rather than being
evaluated and added to the start_test event because the decorator code
only runs after the start_test event is created and sent.  i.e.
LLDBTestResult.startTest() runs before the test method decorators run.

llvm-svn: 255351
diff --git a/lldb/packages/Python/lldbsuite/test/lldbtest.py b/lldb/packages/Python/lldbsuite/test/lldbtest.py
index 0de836d..34481a2 100644
--- a/lldb/packages/Python/lldbsuite/test/lldbtest.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbtest.py
@@ -63,6 +63,8 @@
 from . import lldbutil
 from . import test_categories
 
+from .result_formatter import EventBuilder
+
 # dosep.py starts lots and lots of dotest instances
 # This option helps you find if two (or more) dotest instances are using the same
 # directory at the same time
@@ -784,6 +786,12 @@
         def wrapper(*args, **kwargs):
             from unittest2 import case
             self = args[0]
+            if expected_fn(self):
+                # Send event marking test as explicitly eligible for rerunning.
+                if configuration.results_formatter_object is not None:
+                    # Mark this test as rerunnable.
+                    configuration.results_formatter_object.handle_event(
+                        EventBuilder.event_for_mark_test_rerun_eligible(self))
             try:
                 func(*args, **kwargs)
             # don't retry if the test case is already decorated with xfail or skip
diff --git a/lldb/packages/Python/lldbsuite/test/result_formatter.py b/lldb/packages/Python/lldbsuite/test/result_formatter.py
index a37a1f9..e05714f 100644
--- a/lldb/packages/Python/lldbsuite/test/result_formatter.py
+++ b/lldb/packages/Python/lldbsuite/test/result_formatter.py
@@ -161,6 +161,7 @@
     TYPE_JOB_RESULT = "job_result"
     TYPE_TEST_RESULT = "test_result"
     TYPE_TEST_START = "test_start"
+    TYPE_MARK_TEST_RERUN_ELIGIBLE = "test_eligible_for_rerun"
 
     # Test/Job Status Tags
     STATUS_EXCEPTIONAL_EXIT = "exceptional_exit"
@@ -226,6 +227,7 @@
             "test_name": test_name,
             "test_filename": inspect.getfile(test.__class__)
         })
+
         return event
 
     @staticmethod
@@ -486,6 +488,26 @@
         return event
 
     @staticmethod
+    def event_for_mark_test_rerun_eligible(test):
+        """Creates an event that indicates the specified test is explicitly
+        eligible for rerun.
+
+        Note there is a mode that will enable test rerun eligibility at the
+        global level.  These markings for explicit rerun eligibility are
+        intended for the mode of running where only explicitly rerunnable
+        tests are rerun upon hitting an issue.
+
+        @param test the TestCase instance to which this pertains.
+
+        @return an event that specifies the given test as being eligible to
+        be rerun.
+        """
+        event = EventBuilder._event_dictionary_common(
+            test,
+            EventBuilder.TYPE_MARK_TEST_RERUN_ELIGIBLE)
+        return event
+
+    @staticmethod
     def add_entries_to_all_events(entries_dict):
         """Specifies a dictionary of entries to add to all test events.
 
diff --git a/lldb/packages/Python/lldbsuite/test/test_result.py b/lldb/packages/Python/lldbsuite/test/test_result.py
index ae968e3..b1749eb 100644
--- a/lldb/packages/Python/lldbsuite/test/test_result.py
+++ b/lldb/packages/Python/lldbsuite/test/test_result.py
@@ -13,10 +13,6 @@
 
 # System modules
 import inspect
-import os
-import platform
-import subprocess
-
 
 # Third-party modules
 import unittest2