Add support for Junit tests in platform mode.

build/android/pylib/base/test_run.py

Index: build/android/pylib/base/test_run.py
diff --git a/build/android/pylib/base/test_run.py b/build/android/pylib/base/test_run.py
index 7380e78708670ec01a42f8b3071bd76a0192567d..9b16f890f69cb99b4cca62cbb7f7937c648fe294 100644
--- a/build/android/pylib/base/test_run.py
+++ b/build/android/pylib/base/test_run.py
@@ -25,6 +25,11 @@ class TestRun(object):
     raise NotImplementedError
 
   def RunTests(self):
+    """Runs Tests and returns test results.
+
+    Returns:
+      Should return list of |base_test_result.TestRunResults| objects.
+    """
     raise NotImplementedError
 
   def TearDown(self):