Add modified time checking to strip_library_for_apk.py

build/android/gyp/util/build_utils.py

 # Copyright 2013 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.
 
 import fnmatch
 import json
 import os
 import pipes
 import shlex
 import shutil
@@ skipping 83 matching lines @@
       print stdout,
 
     # Directly exit to avoid printing stacktrace.
     sys.exit(child.returncode)
 
   else:
     if stdout and not suppress_output:
       print stdout,
     return stdout
 
+
+def GetModifiedTime(path):
+  # For a symlink, the modified time should be the greater of the link's
+  # modified time and the modified time of the target.
+  return max(os.lstat(path).st_mtime, os.stat(path).st_mtime)
+
+
+def IsTimeStale(output, inputs):
+  if not os.path.exists(output):
+    return True
+
+  output_time = GetModifiedTime(output)
+  for input in inputs:
+    if GetModifiedTime(input) > output_time:
+      return True
+  return False