Fix chromium testshell crash on startup.

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 34 matching lines @@
 #    that are generated at build time. This should be set automatically by a
 #    target's dependencies. The .java files in these directories are not
 #    included in the 'inputs' list (unlike additional_src_dirs).
 #  input_jars_paths - The path to jars to be included in the classpath. This
 #    should be filled automatically by depending on the appropriate targets.
 #  native_libs_paths - The path to any native library to be included in this
 #    target.
 
 {
   'variables': {
-    'asset_location': '',
+    'asset_location%': '',
     'additional_input_paths': [],
     'input_jars_paths': [],
     'native_libs_paths': [],
     'additional_src_dirs': [],
     'generated_src_dirs': [],
   },
   'actions': [
     {
       'action_name': 'ant_<(package_name)_apk',
       'message': 'Building <(package_name) apk.',
@@ skipping 34 matching lines @@
         '-DPACKAGE_NAME=<(package_name)',
         '-DRESOURCE_DIR=<(resource_dir)',
 
         '-Dbasedir=<(java_in_dir)',
         '-buildfile',
         '<(DEPTH)/build/android/ant/chromium-apk.xml'
       ]
     },
   ],
 }