Android: sync up latest JNI generator changes from downstream.

build/jni_generator.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 generate jni bindings for Java-files in a consistent manner.
 #
 # To use this, create a gyp target with the following form:
 #  {
 #    'target_name': 'base_jni_headers',
@@ skipping 14 matching lines @@
 # (note that RULE_INPUT_ROOT is the basename for the java file).
 #
 # See base/android/jni_generator/jni_generator.py for more info about the
 # format of generating JNI bindings.
 
 {
   'variables': {
     'jni_generator': '<(DEPTH)/base/android/jni_generator/jni_generator.py',
     'jni_generator_jarjar_file%': '',
     'jni_generator_ptr_type%': 'int',
+    # A comma separated string of include files.
+    'jni_generator_includes%': (
+        'base/android/jni_generator/jni_generator_helper.h'
+    ),
   },
   'rules': [
     {
       'rule_name': 'generate_jni_headers',
       'extension': 'java',
       'inputs': [
         '<(jni_generator)',
       ],
       'outputs': [
         '<(SHARED_INTERMEDIATE_DIR)/<(jni_gen_package)/jni/<(RULE_INPUT_ROOT)_jni.h',
       ],
       'action': [
         '<(jni_generator)',
         '--input_file',
         '<(RULE_INPUT_PATH)',
         '--output_dir',
         '<(SHARED_INTERMEDIATE_DIR)/<(jni_gen_package)/jni',
+        '--includes',
+        '<(jni_generator_includes)',
         '--optimize_generation',
         '<(optimize_jni_generation)',
         '--jarjar',
         '<(jni_generator_jarjar_file)',
         '--ptr_type',
         '<(jni_generator_ptr_type)',
       ],
       'message': 'Generating JNI bindings from <(RULE_INPUT_PATH)',
       'process_outputs_as_sources': 1,
       'conditions': [
         ['jni_generator_jarjar_file != ""', {
           'inputs': [
             '<(jni_generator_jarjar_file)',
           ],
         }]
       ],
     },
   ],
   # This target exports a hard dependency because it generates header
   # files.
   'hard_dependency': 1,
 }