Add --allow-downgrade argument for incremental installer.

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
@@ skipping 68 matching lines @@
     cache_path = _DeviceCachePath(device)
     if os.path.exists(cache_path):
       os.unlink(cache_path)
   device.RunShellCommand(['rm', '-rf', _GetDeviceIncrementalDir(package)],
                          check_return=True)
   logging.info('Uninstall took %s seconds.', main_timer.GetDelta())
 
 
 def Install(device, apk, split_globs=None, native_libs=None, dex_files=None,
             enable_device_cache=False, use_concurrency=True,
-            show_proguard_warning=False, permissions=()):
+            show_proguard_warning=False, permissions=(),
+            allow_downgrade=True):
   """Installs the given incremental apk and all required supporting files.
 
   Args:
     device: A DeviceUtils instance.
     apk: The path to the apk, or an ApkHelper instance.
     split_globs: Glob patterns for any required apk splits (optional).
     native_libs: List of app's native libraries (optional).
     dex_files: List of .dex.jar files that comprise the app's Dalvik code.
     enable_device_cache: Whether to enable on-device caching of checksums.
     use_concurrency: Whether to speed things up using multiple threads.
@@ skipping 12 matching lines @@
   device_incremental_dir = _GetDeviceIncrementalDir(apk_package)
 
   # Install .apk(s) if any of them have changed.
   def do_install():
     install_timer.Start()
     if split_globs:
       splits = []
       for split_glob in split_globs:
         splits.extend((f for f in glob.glob(split_glob)))
       device.InstallSplitApk(apk, splits, reinstall=True,
-                             allow_cached_props=True, permissions=permissions)
+                             allow_cached_props=True, permissions=permissions,
+                             allow_downgrade=allow_downgrade)
     else:
-      device.Install(apk, reinstall=True, permissions=permissions)
+      device.Install(apk, reinstall=True, permissions=permissions,
+                     allow_downgrade=allow_downgrade)
     install_timer.Stop(log=False)
 
   # Push .so and .dex files to the device (if they have changed).
   def do_push_files():
     if native_libs:
       push_native_timer.Start()
       with build_utils.TempDir() as temp_dir:
         device_lib_dir = posixpath.join(device_incremental_dir, 'lib')
         for path in native_libs:
           # Note: Can't use symlinks as they don't work when
@@ skipping 130 matching lines @@
                       default=False,
                       help='Print a warning about proguard being disabled')
   parser.add_argument('--dont-even-try',
                       help='Prints this message and exits.')
   parser.add_argument('-v',
                       '--verbose',
                       dest='verbose_count',
                       default=0,
                       action='count',
                       help='Verbose level (multiple times for more)')
+  parser.add_argument('--disable-downgrade',
+                      action='store_false',
+                      default=True,
+                      dest='allow_downgrade',
+                      help='Disable install of apk with lower version number'
+                           'than the version already on the device.')
 
   args = parser.parse_args()
 
   run_tests_helper.SetLogLevel(args.verbose_count)
   constants.SetBuildType('Debug')
   if args.output_directory:
     constants.SetOutputDirectory(args.output_directory)
 
   devil_chromium.Initialize(output_directory=constants.GetOutDirectory())
 
   if args.dont_even_try:
     logging.fatal(args.dont_even_try)
     return 1
 
   # Retries are annoying when commands fail for legitimate reasons. Might want
   # to enable them if this is ever used on bots though.
   device = device_utils.DeviceUtils.HealthyDevices(
       device_arg=args.device,
       default_retries=0,
       enable_device_files_cache=True)[0]
 
   apk = apk_helper.ToHelper(args.apk_path)
   if args.uninstall:
     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)
+            show_proguard_warning=args.show_proguard_warning,
+            allow_downgrade=args.allow_downgrade)
 
 
 if __name__ == '__main__':
   sys.exit(main())