Make resource directory option in gyp template optional.

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 15 matching lines @@
 # content/shell/android/java/content_shell_apk.xml
 # content/shell/android/java/src/chromium/base/Foo.java
 # content/shell/android/java/src/chromium/base/Bar.java
 #
 # Required variables:
 #  package_name - Used to name the intermediate output directory and in the
 #    names of some output files.
 #  apk_name - The final apk will be named <apk_name>-debug.apk (or -release)
 #  java_in_dir - The top-level java directory. The src should be in
 #    <java_in_dir>/src.
-#  resource_dir - The directory for resources.
 # Optional/automatic variables:
 #  additional_input_paths - These paths will be included in the 'inputs' list to
 #    ensure that this target is rebuilt when one of these paths changes.
 #  additional_src_dirs - Additional directories with .java files to be compiled
 #    and included in the output of this target.
 #  asset_location - The directory where assets are located (default:
 #    <PRODUCT_DIR>/<package_name>/assets).
 #  generated_src_dirs - Same as additional_src_dirs except used for .java files
 #    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. This should be a path in <(SHARED_LIB_DIR). A stripped copy of
 #    the library will be included in the apk and symbolic links to the
 #    unstripped copy will be added to <(android_product_out) to enable native
 #    debugging.
+#  resource_dir - The directory for resources.
 
 {
   'variables': {
     'asset_location%': '',
     'additional_input_paths': [],
     'input_jars_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%': '',
     'native_libs_paths': [],
     'manifest_package_name%': 'unknown.package.name',
+    'resource_dir%':'',
   },
   'sources': [
       '<@(native_libs_paths)'
   ],
   'rules': [
     {
       'rule_name': 'copy_and_strip_native_libraries',
       'extension': 'so',
       'variables': {
         'stripped_library_path': '<(PRODUCT_DIR)/<(package_name)/libs/<(android_app_abi)/<(RULE_INPUT_ROOT).so',
@@ skipping 20 matching lines @@
       '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',
         # If there is a separate find for additional_src_dirs, it will find the
         # wrong .java files when additional_src_dirs is empty.
         '>!@(find >(java_in_dir) >(additional_src_dirs) -name "*.java")',
-        '<!@(find <(java_in_dir)/<(resource_dir) -name "*")',
         '>@(input_jars_paths)',
         '>@(native_libs_paths)',
         '>@(additional_input_paths)',
       ],
+      'conditions': [
+        ['resource_dir!=""', {
+          'inputs': ['<!@(find <(java_in_dir)/<(resource_dir) -name "*")']
+        }],
+      ],
       'outputs': [
         # TODO(cjhopman): Apks are built with a -debug suffix even when they are
         # built in release. This should be fixed.
         '<(PRODUCT_DIR)/apks/<(apk_name)-debug.apk',
       ],
       'action': [
         'ant',
         '-DAPP_ABI=<(android_app_abi)',
         '-DANDROID_GDBSERVER=<(android_gdbserver)',
         '-DANDROID_SDK=<(android_sdk)',
@@ skipping 21 matching lines @@
         '-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)',
       ]
     },
   ],
 }