[Android] Add gn support for multidex.

build/android/gyp/main_dex_list.py

Index: build/android/gyp/main_dex_list.py
diff --git a/build/android/gyp/main_dex_list.py b/build/android/gyp/main_dex_list.py
index 7f29bfb50d4e235e7c9d3c7bd6ba58548f31a7d8..7388f4abdb53e7dab4aa367603f67935596b7e6c 100755
--- a/build/android/gyp/main_dex_list.py
+++ b/build/android/gyp/main_dex_list.py
@@ -17,8 +17,9 @@ sys.path.append(os.path.abspath(os.path.join(
 from pylib import constants
 
 
-def main():
+def main(args):
   parser = argparse.ArgumentParser()
+  build_utils.AddDepfileOption(parser)
   parser.add_argument('--android-sdk-tools', required=True,
                       help='Android sdk build tools directory.')
   parser.add_argument('--main-dex-rules-path', action='append', default=[],
@@ -36,11 +37,14 @@ def main():
   parser.add_argument('--multidex-configuration-path',
                       help='A JSON file containing multidex build '
                            'configuration.')
-  parser.add_argument('paths', nargs='+',
+  parser.add_argument('--inputs',
+                      help='JARs for which a main dex list should be '
+                           'generated.')
+  parser.add_argument('paths', nargs='*', default=[],
                       help='JARs for which a main dex list should be '
                            'generated.')
 
-  args = parser.parse_args()
+  args = parser.parse_args(build_utils.ExpandFileArgs(args))
 
   if args.multidex_configuration_path:
     with open(args.multidex_configuration_path) as multidex_config_file:
@@ -49,52 +53,86 @@ def main():
     if not multidex_config.get('enabled', False):
       return 0
 
-  with open(args.main_dex_list_path, 'w') as main_dex_list_file:
+  if args.inputs:
+    args.paths.extend(build_utils.ParseGypList(args.inputs))
+
+  shrinked_android_jar = os.path.abspath(
+      os.path.join(args.android_sdk_tools, 'lib', 'shrinkedAndroid.jar'))
+  dx_jar = os.path.abspath(
+      os.path.join(args.android_sdk_tools, 'lib', 'dx.jar'))
+  rules_file = os.path.abspath(
+      os.path.join(args.android_sdk_tools, 'mainDexClasses.rules'))
+
+  proguard_cmd = [
+    constants.PROGUARD_SCRIPT_PATH,
+    '-forceprocessing',
+    '-dontwarn', '-dontoptimize', '-dontobfuscate', '-dontpreverify',
+    '-libraryjars', shrinked_android_jar,
+    '-include', rules_file,
+  ]
+  for m in args.main_dex_rules_paths:
+    proguard_cmd.extend(['-include', m])
+
+  main_dex_list_cmd = [
+    'java', '-cp', dx_jar,
+    'com.android.multidex.MainDexListBuilder',
+  ]
+
+  input_paths = list(args.paths)
+  input_paths += [
+    shrinked_android_jar,
+    dx_jar,
+    rules_file,
+  ]
+  input_paths += args.main_dex_rules_paths
+
+  input_strings = [
+    proguard_cmd,
+    main_dex_list_cmd,
+  ]
+
+  output_paths = [
+    args.main_dex_list_path,
+  ]
+
+  build_utils.CallAndWriteDepfileIfStale(
+      lambda: _OnStaleMd5(proguard_cmd, main_dex_list_cmd, args.paths,
+                          args.main_dex_list_path),
+      args,
+      input_paths=input_paths,
+      input_strings=input_strings,
+      output_paths=output_paths)
+
+  return 0
 
-    shrinked_android_jar = os.path.abspath(
-        os.path.join(args.android_sdk_tools, 'lib', 'shrinkedAndroid.jar'))
-    dx_jar = os.path.abspath(
-        os.path.join(args.android_sdk_tools, 'lib', 'dx.jar'))
-    paths_arg = ':'.join(args.paths)
-    rules_file = os.path.abspath(
-        os.path.join(args.android_sdk_tools, 'mainDexClasses.rules'))
 
+def _OnStaleMd5(proguard_cmd, main_dex_list_cmd, paths, main_dex_list_path):
+  paths_arg = ':'.join(paths)
+  main_dex_list = ''
+  try:
     with tempfile.NamedTemporaryFile(suffix='.jar') as temp_jar:
-      proguard_cmd = [
-        constants.PROGUARD_SCRIPT_PATH,
-        '-forceprocessing',
-        '-dontwarn', '-dontoptimize', '-dontobfuscate', '-dontpreverify',
+      proguard_cmd += [
         '-injars', paths_arg,
-        '-outjars', temp_jar.name,
-        '-libraryjars', shrinked_android_jar,
-        '-include', rules_file,
+        '-outjars', temp_jar.name
       ]
-      for m in args.main_dex_rules_paths:
-        proguard_cmd.extend(['-include', m])
-
-      main_dex_list = ''
-      try:
-        build_utils.CheckOutput(proguard_cmd, print_stderr=False)
-
-        java_cmd = [
-          'java', '-cp', dx_jar,
-          'com.android.multidex.MainDexListBuilder',
-          temp_jar.name, paths_arg
-        ]
-        main_dex_list = build_utils.CheckOutput(java_cmd)
-      except build_utils.CalledProcessError as e:
-        if 'output jar is empty' in e.output:
-          pass
-        elif "input doesn't contain any classes" in e.output:
-          pass
-        else:
-          raise
-
-      main_dex_list_file.write(main_dex_list)
+      build_utils.CheckOutput(proguard_cmd, print_stderr=False)
 
-  return 0
+      main_dex_list_cmd += [
+        temp_jar.name, paths_arg
+      ]
+      main_dex_list = build_utils.CheckOutput(main_dex_list_cmd)
+  except build_utils.CalledProcessError as e:
+    if 'output jar is empty' in e.output:
+      pass
+    elif "input doesn't contain any classes" in e.output:
+      pass
+    else:
+      raise
+
+  with open(main_dex_list_path, 'w') as main_dex_list_file:
+    main_dex_list_file.write(main_dex_list)
 
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(main(sys.argv[1:]))