Add support for proguard preprocessing.

build/android/gyp/proguard.py

Index: build/android/gyp/proguard.py
diff --git a/build/android/gyp/proguard.py b/build/android/gyp/proguard.py
new file mode 100755
index 0000000000000000000000000000000000000000..6268caff18274077cbde490a02dd1cff9fd447c0
--- /dev/null
+++ b/build/android/gyp/proguard.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+#
+# Copyright 2013 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.
+
+import fnmatch
+import optparse
+import os
+import sys
+
+from util import build_utils
+
+def DoProguard(options):
+  injars = options.input_path
+  outjars = options.output_path
+  classpath = build_utils.ParseGypList(options.classpath)
+  classpath = list(set(classpath))
+  libraryjars = ':'.join(classpath)
+  # proguard does its own dependency checking, which can be avoided by deleting
+  # the output.
+  if os.path.exists(options.output_path):
+    os.remove(options.output_path)
+  proguard_cmd = [options.proguard_path,
+                  '-injars', injars,
+                  '-outjars', outjars,
+                  '-libraryjars', libraryjars,
+                  '@' + options.proguard_config]
+  build_utils.CheckCallDie(proguard_cmd)
+
+def main(argv):
+  parser = optparse.OptionParser()
+  parser.add_option('--proguard-path',
+                    help='Path to the proguard executable.')
+  parser.add_option('--input-path',
+                    help='Path to the .jar file proguard should run on.')
+  parser.add_option('--output-path', help='Path to the generated .jar file.')
+  parser.add_option('--proguard-config',
+                    help='Path to the proguard configuration file.')
+  parser.add_option('--classpath', help="Classpath for proguard.")
+  parser.add_option('--stamp', help='Path to touch on success.')
+
+  # TODO(newt): remove this once http://crbug.com/177552 is fixed in ninja.
+  parser.add_option('--ignore', help='Ignored.')
+
+  options, _ = parser.parse_args()
+
+  DoProguard(options)
+
+  if options.stamp:
+    build_utils.Touch(options.stamp)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))