Add Proguard option to gyp template.

build/java_apk.gypi

 # Copyright (c) 2012 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.
 
 # This file is meant to be included into a target to provide a rule
 # to build Android APKs in a consistent manner.
 #
 # To use this, create a gyp target with the following form:
 # {
 #   'target_name': 'my_package_apk',
@@ skipping 40 matching lines @@
 #    target.
 
 {
   'variables': {
     'asset_location%': '',
     'additional_input_paths': [],
     'input_jars_paths': [],
     'native_libs_paths': [],
     'additional_src_dirs': [],
     'generated_src_dirs': [],
+    'app_manifest_version_name%': '<(android_app_version_name)',
+    'app_manifest_version_code%': '<(android_app_version_code)',
+    'proguard_enabled%': 'false',
+    'proguard_flags%': ''
   },
   'actions': [
     {
       'action_name': 'ant_<(package_name)_apk',
       'message': 'Building <(package_name) apk.',
       'inputs': [
         '<(java_in_dir)/AndroidManifest.xml',
         '<(DEPTH)/build/android/ant/chromium-apk.xml',
         '<(DEPTH)/build/android/ant/common.xml',
         '<(DEPTH)/build/android/ant/sdk-targets.xml',
@@ skipping 23 matching lines @@
         '-DCONFIGURATION_NAME=<(CONFIGURATION_NAME)',
         '-DPRODUCT_DIR=<(ant_build_out)',
 
         '-DAPK_NAME=<(apk_name)',
         '-DASSET_DIR=<(asset_location)',
         '-DADDITIONAL_SRC_DIRS=>(additional_src_dirs)',
         '-DGENERATED_SRC_DIRS=>(generated_src_dirs)',
         '-DINPUT_JARS_PATHS=>(input_jars_paths)',
         '-DPACKAGE_NAME=<(package_name)',
         '-DRESOURCE_DIR=<(resource_dir)',
+        '-DAPP_MANIFEST_VERSION_NAME=<(app_manifest_version_name)',
+        '-DAPP_MANIFEST_VERSION_CODE=<(app_manifest_version_code)',
+        '-DPROGUARD_FLAGS=>(proguard_flags)',
+        '-DPROGUARD_ENABLED=>(proguard_enabled)',
 
         '-Dbasedir=<(java_in_dir)',
         '-buildfile',
         '<(DEPTH)/build/android/ant/chromium-apk.xml',
 
         # Specify CONFIGURATION_NAME as the target for ant to build. The
         # buildfile will then build the appropriate SDK tools target.
         '<(CONFIGURATION_NAME)',
       ]
     },
   ],
 }