[Android] Rework instrumentation test skipping and result generation.

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 508b9887948eb2a7ea6ea5abe2690cc3b791addb..58200f6d49535b64426b6d5160b01e7a3a010241 100644
--- a/build/android/pylib/base/base_test_result.py
+++ b/build/android/pylib/base/base_test_result.py
@@ -77,6 +77,10 @@ class BaseTestResult(object):
     """Get the test duration."""
     return self._duration
 
+  def SetLog(self, log):
+    """Set the test log."""
+    self._log = log
+
   def GetLog(self):
     """Get the test log."""
     return self._log