Update from https://crrev.com/304121

build/android/pylib/instrumentation/test_jar.py

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Helper class for instrumenation test jar."""
 # pylint: disable=W0702
 
 import logging
 import os
 import pickle
 import re
 import sys
 import tempfile
 
 from pylib import cmd_helper
 from pylib import constants
 from pylib.device import device_utils
 
 sys.path.insert(0,
                 os.path.join(constants.DIR_SOURCE_ROOT,
                              'build', 'util', 'lib', 'common'))
 
 import unittest_util # pylint: disable=F0401
 
 # If you change the cached output of proguard, increment this number
-PICKLE_FORMAT_VERSION = 2
+PICKLE_FORMAT_VERSION = 3
 
 
 class TestJar(object):
   _ANNOTATIONS = frozenset(
       ['Smoke', 'SmallTest', 'MediumTest', 'LargeTest', 'EnormousTest',
        'FlakyTest', 'DisabledTest', 'Manual', 'PerfTest', 'HostDrivenTest',
        'IntegrationTest'])
   _DEFAULT_ANNOTATION = 'SmallTest'
   _PROGUARD_CLASS_RE = re.compile(r'\s*?- Program class:\s*([\S]+)$')
   _PROGUARD_SUPERCLASS_RE = re.compile(r'\s*?  Superclass:\s*([\S]+)$')
@@ skipping 11 matching lines @@
                                        'tools/proguard/lib/proguard.jar')
     if not os.path.exists(self._PROGUARD_PATH):
       self._PROGUARD_PATH = os.path.join(os.environ['ANDROID_BUILD_TOP'],
                                          'external/proguard/lib/proguard.jar')
     self._jar_path = jar_path
     self._pickled_proguard_name = self._jar_path + '-proguard.pickle'
     self._test_methods = {}
     if not self._GetCachedProguardData():
       self._GetProguardData()
 
+  @staticmethod
+  def _CalculateMd5(path):
+    # TODO(jbudorick): Move MD5sum calculations out of here and
+    # AndroidCommands to their own module.
+    out = cmd_helper.GetCmdOutput(
+        [os.path.join(constants.GetOutDirectory(),
+                      'md5sum_bin_host'),
+        path])
+    return out
+
   def _GetCachedProguardData(self):
     if (os.path.exists(self._pickled_proguard_name) and
         (os.path.getmtime(self._pickled_proguard_name) >
          os.path.getmtime(self._jar_path))):
       logging.info('Loading cached proguard output from %s',
                    self._pickled_proguard_name)
       try:
         with open(self._pickled_proguard_name, 'r') as r:
           d = pickle.loads(r.read())
-        if d['VERSION'] == PICKLE_FORMAT_VERSION:
+        jar_md5 = self._CalculateMd5(self._jar_path)
+        if (d['JAR_MD5SUM'] == jar_md5 and
+            d['VERSION'] == PICKLE_FORMAT_VERSION):
           self._test_methods = d['TEST_METHODS']
           return True
       except:
         logging.warning('PICKLE_FORMAT_VERSION has changed, ignoring cache')
     return False
 
   def _GetProguardData(self):
     logging.info('Retrieving test methods via proguard.')
 
     with tempfile.NamedTemporaryFile() as proguard_output:
@@ skipping 97 matching lines @@
                   annotation_name + ':' + annotation_value)
           self._test_methods[qualified_method] = {
             'annotations': method_annotations
           }
           if min_sdk_level is not None:
             self._test_methods[qualified_method]['min_sdk_level'] = (
                 int(min_sdk_level))
 
     logging.info('Storing proguard output to %s', self._pickled_proguard_name)
     d = {'VERSION': PICKLE_FORMAT_VERSION,
-         'TEST_METHODS': self._test_methods}
+         'TEST_METHODS': self._test_methods,
+         'JAR_MD5SUM': self._CalculateMd5(self._jar_path)}
     with open(self._pickled_proguard_name, 'w') as f:
       f.write(pickle.dumps(d))
 
 
   @staticmethod
   def _IsTestMethod(test):
     class_name, method = test.split('#')
     return class_name.endswith('Test') and method.startswith('test')
 
   def GetTestAnnotations(self, test):
@@ skipping 103 matching lines @@
             'ro.build.version.sdk').pGet(None)]
     tests = filter(
         lambda t: self._IsTestValidForSdkRange(t, min(sdk_versions)),
         tests)
 
     return tests
 
   @staticmethod
   def IsHostDrivenTest(test):
     return 'pythonDrivenTests' in test