[Android] Add chrome_java target for building Java code in the chromium layer.

build/java.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 Java in a consistent manner.
 #
 # To use this, create a gyp target with the following form:
 # {
 #   'target_name': 'my-package_java',
@@ skipping 29 matching lines @@
          '<!@(find <(java_in_dir) -name "*.java")'
       ],
       'outputs': [
         '<(PRODUCT_DIR)/lib.java/chromium_<(package_name).jar',
       ],
       'action': [
         'ant',
         '-DPRODUCT_DIR=<(ant_build_out)',
         '-DPACKAGE_NAME=<(package_name)',
         '-DANDROID_SDK=<(android_sdk)',
+        '-DANDROID_SDK_ROOT=<(android_sdk_root)',
+        '-DANDROID_SDK_TOOLS=<(android_sdk_tools)',
+        '-DANDROID_SDK_VERSION=<(android_sdk_version)',
+        '-DANDROID_TOOLCHAIN=<(android_toolchain)',
         '-buildfile',
         '<(java_in_dir)/<(package_name).xml',
       ]
     },
   ],
 }