GN: Fix placeholders having double .so extension and breaking rezip

build/android/gyp/apkbuilder.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2015 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.
 
 """Adds the code parts to a resource APK."""
 
 import argparse
 import itertools
@@ skipping 195 matching lines @@
           build_utils.AddToZipHermetic(out_apk, 'classes.dex',
                                        src_path=options.dex_file)
 
         # 5. Native libraries.
         for path in native_libs:
           basename = os.path.basename(path)
           apk_path = 'lib/%s/%s' % (options.android_abi, basename)
           build_utils.AddToZipHermetic(out_apk, apk_path, src_path=path)
 
         for name in sorted(options.native_lib_placeholders):
-          # Make it non-empty so that its checksum is non-zero and is not
-          # ignored by md5_check.
-          apk_path = 'lib/%s/%s.so' % (options.android_abi, name)
-          build_utils.AddToZipHermetic(out_apk, apk_path, data=':)')
+          # Empty libs files are ignored by md5check, but rezip requires them
+          # to be empty in order to identify them as placeholders.
+          apk_path = 'lib/%s/%s' % (options.android_abi, name)
+          build_utils.AddToZipHermetic(out_apk, apk_path, data='')
 
         # 6. Java resources. Used only when coverage is enabled, so order
         # doesn't matter).
         if options.emma_device_jar:
           # Add EMMA Java resources to APK.
           with zipfile.ZipFile(options.emma_device_jar, 'r') as emma_device_jar:
             for apk_path in emma_device_jar.namelist():
               apk_path_lower = apk_path.lower()
               if apk_path_lower.startswith('meta-inf/'):
                 continue
@@ skipping 15 matching lines @@
   build_utils.CallAndWriteDepfileIfStale(
       on_stale_md5,
       options,
       input_paths=input_paths,
       input_strings=input_strings,
       output_paths=[options.output_apk])
 
 
 if __name__ == '__main__':
   main(sys.argv[1:])