[test-runner] Move test case processing beyond the multi-process boundary.

tools/testrunner/objects/testcase.py

Index: tools/testrunner/objects/testcase.py
diff --git a/tools/testrunner/objects/testcase.py b/tools/testrunner/objects/testcase.py
index 0ab06361b178546c232f4883bd57d28dd1e53f07..fa2265c0703f1fecd028fde43b988d3cc54ebf01 100644
--- a/tools/testrunner/objects/testcase.py
+++ b/tools/testrunner/objects/testcase.py
@@ -86,3 +86,11 @@ class TestCase(object):
 
   def GetLabel(self):
     return self.suitename() + "/" + self.suite.CommonTestName(self)
+
+  def __getstate__(self):
+    """Representation to pickle test cases.
+
+    The original suite won't be sent beyond process boundaries. Instead
+    send the name only and retrieve a process-local suite later.
+    """
+    return dict(self.__dict__, suite=self.suite.name)