Add java-side support for _incremental instrumentation tests

build/android/incremental_install/installer.py

 #!/usr/bin/env python
 #
 # Copyright 2015 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.
 
 """Install *_incremental.apk targets as well as their dependent files."""
 
 import argparse
 import glob
 import logging
 import os
 import posixpath
 import shutil
 import sys
+import zipfile
 
 sys.path.append(
     os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir)))
 import devil_chromium
 from devil.android import apk_helper
 from devil.android import device_utils
 from devil.android import device_errors
 from devil.android.sdk import version_codes
 from devil.utils import reraiser_thread
 from pylib import constants
@@ skipping 30 matching lines @@
       f()
   timer.Stop(log=False)
   return timer
 
 
 def _GetDeviceIncrementalDir(package):
   """Returns the device path to put incremental files for the given package."""
   return '/data/local/tmp/incremental-app-%s' % package
 
 
+def _HasClasses(jar_path):
+  """Returns whether the given jar contains classes.dex."""
+  with zipfile.ZipFile(jar_path) as jar:
+    return 'classes.dex' in jar.namelist()
+
+
 def Uninstall(device, package, enable_device_cache=False):
   """Uninstalls and removes all incremental files for the given package."""
   main_timer = time_profile.TimeProfile()
   device.Uninstall(package)
   if enable_device_cache:
     # Uninstall is rare, so just wipe the cache in this case.
     cache_path = _DeviceCachePath(device)
     if os.path.exists(cache_path):
       os.unlink(cache_path)
   device.RunShellCommand(['rm', '-rf', _GetDeviceIncrementalDir(package)],
@@ skipping 55 matching lines @@
 
     if dex_files:
       push_dex_timer.Start()
       # Put all .dex files to be pushed into a temporary directory so that we
       # can use delete_device_stale=True.
       with build_utils.TempDir() as temp_dir:
         device_dex_dir = posixpath.join(device_incremental_dir, 'dex')
         # Ensure no two files have the same name.
         transformed_names = _TransformDexPaths(dex_files)
         for src_path, dest_name in zip(dex_files, transformed_names):
-          shutil.copy(src_path, os.path.join(temp_dir, dest_name))
+          # Binary targets with no extra classes create .dex.jar without a
+          # classes.dex (which Android chokes on).
+          if _HasClasses(src_path):
+            shutil.copy(src_path, os.path.join(temp_dir, dest_name))
         device.PushChangedFiles([(temp_dir, device_dex_dir)],
                                 delete_device_stale=True)
       push_dex_timer.Stop(log=False)
 
   def check_selinux():
     # Marshmallow has no filesystem access whatsoever. It might be possible to
     # get things working on Lollipop, but attempts so far have failed.
     # http://crbug.com/558818
     has_selinux = device.build_version_sdk >= version_codes.LOLLIPOP
     if has_selinux and apk.HasIsolatedProcesses():
@@ skipping 143 matching lines @@
     Uninstall(device, apk.GetPackageName(), enable_device_cache=args.cache)
   else:
     Install(device, apk, split_globs=args.splits, native_libs=args.native_libs,
             dex_files=args.dex_files, enable_device_cache=args.cache,
             use_concurrency=args.threading,
             show_proguard_warning=args.show_proguard_warning)
 
 
 if __name__ == '__main__':
   sys.exit(main())