Add tombstones as part of json-results-file for android instr tests.

build/android/pylib/base/base_test_result.py

Index: build/android/pylib/base/base_test_result.py
diff --git a/build/android/pylib/base/base_test_result.py b/build/android/pylib/base/base_test_result.py
index dabe132b8b107a48fd35c9849181ce706ea80069..333211fa3219480837e4bbc38d5140e70ac57da7 100644
--- a/build/android/pylib/base/base_test_result.py
+++ b/build/android/pylib/base/base_test_result.py
@@ -41,6 +41,7 @@ class BaseTestResult(object):
     self._test_type = test_type
     self._duration = duration
     self._log = log
+    self._tombstones = None
 
   def __str__(self):
     return self._name
@@ -88,6 +89,11 @@ class BaseTestResult(object):
     """Get the test log."""
     return self._log
 
+  def SetTombstones(self, tombstones):
+    self._tombstones = tombstones
+
+  def GetTombstones(self):
+    return self._tombstones
 
 class TestRunResults(object):
   """Set of results for a test run."""