Update from https://crrev.com/311076

base/android/jni_generator/jni_generator.py

 #!/usr/bin/env python
 # 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.
 
 """Extracts native methods from a Java file and generates the JNI bindings.
 If you change this, please run and update the tests."""
 
 import collections
 import errno
@@ skipping 1019 matching lines @@
         JavaDataTypeToCForCalledByNativeParam(param.datatype) + ' ' +
         param.name
         for param in called_by_native.params])
 
   def GetForwardDeclaration(self, native):
     template_str = """
 static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS});
 """
     if self.options.native_exports:
       template_str += """
-__attribute__((visibility("default")))
-${RETURN} Java_${JAVA_NAME}_native${NAME}(JNIEnv* env, ${PARAMS}) {
-  return ${NAME}(${PARAMS_IN_CALL});
-}
+__attribute__((visibility("default"), alias("${NAME}")))
+${RETURN} Java_${JAVA_NAME}_native${NAME}(JNIEnv* env, ${PARAMS});
 """
     template = Template(template_str)
     params_in_call = []
     if not self.options.pure_native_methods:
       params_in_call = ['env', 'jcaller']
     params_in_call = ', '.join(params_in_call + [p.name for p in native.params])
 
     java_name = JniParams.RemapClassName(self.fully_qualified_class)
     java_name = java_name.replace('_', '_1').replace('/', '_')
     if native.java_class_name:
@@ skipping 206 matching lines @@
           'JAVA_CLASS': clazz,
           'JNI_CLASS_PATH': JniParams.RemapClassName(all_classes[clazz]),
       }
       ret += [template.substitute(values)]
     ret += ''
 
     class_getter_methods = []
     if self.options.native_exports:
       template = Template("""\
 // Leaking this jclass as we cannot use LazyInstance from some threads.
-base::subtle::AtomicWord g_${JAVA_CLASS}_clazz = 0;
+base::subtle::AtomicWord g_${JAVA_CLASS}_clazz __attribute__((unused)) = 0;
 #define ${JAVA_CLASS}_clazz(env) \
 base::android::LazyGetClass(env, k${JAVA_CLASS}ClassPath, \
 &g_${JAVA_CLASS}_clazz)""")
     else:
       template = Template("""\
 // Leaking this jclass as we cannot use LazyInstance from some threads.
 jclass g_${JAVA_CLASS}_clazz = NULL;
 #define ${JAVA_CLASS}_clazz(env) g_${JAVA_CLASS}_clazz""")
 
     for clazz in called_by_native_classes:
@@ skipping 237 matching lines @@
   GenerateJNIHeader(input_file, output_file, options)
 
   if options.depfile:
     build_utils.WriteDepfile(
         options.depfile,
         build_utils.GetPythonDependencies())
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))