Added the --screenshot option.

build/android/pylib/local/device/local_device_instrumentation_test_run.py

Index: build/android/pylib/local/device/local_device_instrumentation_test_run.py
diff --git a/build/android/pylib/local/device/local_device_instrumentation_test_run.py b/build/android/pylib/local/device/local_device_instrumentation_test_run.py
index 2d574de1fd2017149062cb63c9c4eb12e6023bad..09ce6bf91fe7fffec4c04f7a8aa42f119ba045c3 100644
--- a/build/android/pylib/local/device/local_device_instrumentation_test_run.py
+++ b/build/android/pylib/local/device/local_device_instrumentation_test_run.py
@@ -3,11 +3,13 @@
 # found in the LICENSE file.
 
 import logging
+import os
 import re
 import time
 
 from devil.android import device_errors
 from devil.android import flag_changer
+from devil.android.device_utils import _GetTimeStamp

[BigBossZhiling, 2016/05/19 00:43:10]

If I just do, from devil.android import device_utils, and then call it by
'device_utils._GetTimeStamp()', presubmit checks will fail, saying calling
protected method blah blah blah.

[mikecase (-- gone --), 2016/05/19 00:49:27]

You should change the name to GetTimeStamp if you are going to use that
function.
The underscore is supposed to indicate that it is a private function.

But tbh, that GetTimeStamp function probably shouldnt be a public api in
device_utils since it doesnt get the time from the device or anything related to
teh device. You probably should move it somewhere in devil/utils/ when
making it public.

After you change the name you should change the import to just
from devil.android import device_utils

[jbudorick, 2016/05/19 18:11:42]

No, don't do this, and don't use _GetTimeStamp. Just do something similar to
what it does w/ strftime

[BigBossZhiling, 2016/05/19 18:23:49]

Done.

 from devil.utils import reraiser_thread
 from pylib import valgrind_tools
 from pylib.base import base_test_result
@@ -263,6 +265,12 @@ class LocalDeviceInstrumentationTestRun(
     if any(r.GetType() not in (base_test_result.ResultType.PASS,
                                base_test_result.ResultType.SKIP)
            for r in results):
+      if self._test_instance.screenshot_dir:
+        file_name = '%s-%s.png' % (test_display_name, _GetTimeStamp())
+        saved_dir = device.TakeScreenshot(
+          os.path.join(self._test_instance.screenshot_dir, file_name))
+        logging.info('Saved screenshot for %s to %s.',
+          test_display_name, saved_dir)
       logging.info('detected failure in %s. raw output:', test_display_name)
       for l in output:
         logging.info('  %s', l)