GN incremental install: Add a --no-cache flag

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 56 matching lines @@
                       action='store_true',
                       default=False,
                       help='Remove the app and all side-loaded files.')
   parser.add_argument('--output-directory',
                       help='Path to the root build directory.')
   parser.add_argument('--no-threading',
                       action='store_false',
                       default=True,
                       dest='threading',
                       help='Do not install and push concurrently')
+  parser.add_argument('--no-cache',
+                      action='store_false',
+                      default=True,
+                      dest='cache',
+                      help='Do not use cached information about what files are '
+                           'currently on the target device.')
   parser.add_argument('-v',
                       '--verbose',
                       dest='verbose_count',
                       default=0,
                       action='count',
                       help='Verbose level (multiple times for more)')
 
   args = parser.parse_args()
 
   run_tests_helper.SetLogLevel(args.verbose_count)
@@ skipping 83 matching lines @@
     if has_selinux and apk_help.HasIsolatedProcesses():
       raise Exception('Cannot use incremental installs on versions of Android '
                       'where isoloated processes cannot access the filesystem '
                       '(this includes Android M+, and Samsung L+) without '
                       'first disabling isoloated processes.\n'
                       'To do so, use GN arg:\n'
                       '    disable_incremental_isolated_processes=true')
 
   cache_path = '%s/files-cache.json' % device_incremental_dir
   def restore_cache():
+    if not args.cache:
+      logging.info('Ignoring device cache')
+      return
     # Delete the cached file so that any exceptions cause the next attempt
     # to re-compute md5s.
     cmd = 'P=%s;cat $P 2>/dev/null && rm $P' % cache_path
     lines = device.RunShellCommand(cmd, check_return=False, large_output=True)
     if lines:
       device.LoadCacheData(lines[0])
     else:
       logging.info('Device cache not found: %s', cache_path)
 
   def save_cache():
@@ skipping 29 matching lines @@
   logging.info(
       'Took %s seconds (setup=%s, install=%s, libs=%s, dex=%s, finalize=%s)',
       main_timer.GetDelta(), setup_timer.GetDelta(), install_timer.GetDelta(),
       push_native_timer.GetDelta(), push_dex_timer.GetDelta(),
       finalize_timer.GetDelta())
 
 
 if __name__ == '__main__':
   sys.exit(main())