Fix generate_split_manifest.py depending on third-party "lxml" import

build/android/gyp/generate_split_manifest.py

 #!/usr/bin/env python
 #
 # Copyright 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.
 """Creates an AndroidManifest.xml for an APK split.
 
 Given the manifest file for the main APK, generates an AndroidManifest.xml with
 the value required for a Split APK (package, versionCode, etc).
 """
 
-import lxml.etree
 import optparse
+import xml.etree.ElementTree
 
 from util import build_utils
 
 MANIFEST_TEMPLATE = """<?xml version="1.0" encoding="utf-8"?>
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="%(package)s"
     split="%(split)s">
   <uses-sdk android:minSdkVersion="21" />
   <application android:hasCode="%(has_code)s">
@@ skipping 35 matching lines @@
 
   Args:
     main_manifest: the XML manifest of the main APK as a string
     split: the name of the split as a string
     has_code: whether this split APK will contain .dex files
 
   Returns:
     The XML split manifest as a string
   """
 
-  doc = lxml.etree.fromstring(main_manifest)
-  package = doc.xpath('/manifest/@package')[0]
+  doc = xml.etree.ElementTree.fromstring(main_manifest)
+  package = doc.get('package')
 
   return MANIFEST_TEMPLATE % {
       'package': package,
       'split': split.replace('-', '_'),
       'has_code': str(has_code).lower()
   }
 
 
 def main():
   options = ParseArgs()
   main_manifest = file(options.main_manifest).read()
   split_manifest = Build(
       main_manifest,
       options.split,
       options.has_code)
 
   with file(options.out_manifest, 'w') as f:
     f.write(split_manifest)
 
   if options.depfile:
     build_utils.WriteDepfile(
         options.depfile,
         [options.main_manifest] + build_utils.GetPythonDependencies())
 
 
 if __name__ == '__main__':
   main()