[android] Instumentation tests determine whether to install test apk based on Md5Sum.

build/android/pylib/gtest/test_package_apk.py

 # Copyright (c) 2012 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.
 
 """Defines TestPackageApk to help run APK-based native tests."""
 
 import logging
 import os
 import shlex
 import sys
@@ skipping 64 matching lines @@
     return pexpect.spawn('adb', args, timeout=timeout, logfile=logfile)
 
   def _StartActivity(self):
     self.adb.StartActivity(
         self._test_apk_package_name,
         self._test_activity_name,
         wait_for_completion=True,
         action='android.intent.action.MAIN',
         force_stop=True)
 
-  def _NeedsInstall(self):
-    installed_apk_path = self.adb.GetApplicationPath(
-        self._test_apk_package_name)
-    if installed_apk_path:
-      return not self.adb.CheckMd5Sum(
-          self.test_suite_full, installed_apk_path, ignore_paths=True)
-    else:
-      return True
-
   def _GetTestSuiteBaseName(self):
     """Returns the  base name of the test suite."""
     # APK test suite names end with '-debug.apk'
     return os.path.basename(self.test_suite).rsplit('-debug', 1)[0]
 
   #override
   def ClearApplicationState(self):
     self.adb.ClearApplicationState(self._test_apk_package_name)
 
   #override
@@ skipping 26 matching lines @@
       self._ClearFifo()
       self._StartActivity()
     finally:
       self.tool.CleanUpEnvironment()
     logfile = android_commands.NewLineNormalizer(sys.stdout)
     return self._WatchFifo(timeout=10, logfile=logfile)
 
   #override
   def Install(self):
     self.tool.CopyFiles()
-    if self._NeedsInstall():
-      # Always uninstall the previous one (by activity name); we don't
-      # know what was embedded in it.
-      self.adb.ManagedInstall(self.test_suite_full, False,
-                              package_name=self._test_apk_package_name)
+    self.adb.ManagedInstall(self.test_suite_full, False,
+                            package_name=self._test_apk_package_name)