Re-invent page aligning libraries in APK file.

build/android/gyp/finalize_apk.py

Index: build/android/gyp/finalize_apk.py
diff --git a/build/android/gyp/finalize_apk.py b/build/android/gyp/finalize_apk.py
index e66eac67e263baf4be4953f7e3b4702b13249102..bf31a54a78ebf04001db1398ecf044401b7e583a 100755
--- a/build/android/gyp/finalize_apk.py
+++ b/build/android/gyp/finalize_apk.py
@@ -14,17 +14,33 @@ import tempfile
 
 from util import build_utils
 
-def RenameLibInApk(rezip_path, in_zip_file, out_zip_file):
-  rename_cmd = [
-      rezip_path,
-      'rename',
+def AddPageAlignment(rezip_apk_jar_path, in_zip_file, out_zip_file):
+  rezip_apk_cmd = [
+      'java',
+      '-classpath',
+      rezip_apk_jar_path,
+      'RezipApk',
+      'addalignment',
       in_zip_file,
       out_zip_file,
     ]
-  build_utils.CheckOutput(rename_cmd)
+  build_utils.CheckOutput(rezip_apk_cmd)
+
+
+def ReorderAndAlignApk(rezip_apk_jar_path, in_zip_file, out_zip_file):
+  rezip_apk_cmd = [
+      'java',
+      '-classpath',
+      rezip_apk_jar_path,
+      'RezipApk',
+      'reorder',
+      in_zip_file,
+      out_zip_file,
+    ]
+  build_utils.CheckOutput(rezip_apk_cmd)
 
 
-def SignApk(key_path, key_name, key_passwd, unsigned_path, signed_path):
+def JarSigner(key_path, key_name, key_passwd, unsigned_path, signed_path):
   shutil.copy(unsigned_path, signed_path)
   sign_cmd = [
       'jarsigner',
@@ -48,20 +64,10 @@ def AlignApk(zipalign_path, unaligned_path, final_path):
   build_utils.CheckOutput(align_cmd)
 
 
-def UncompressLibAndPageAlignInApk(rezip_path, in_zip_file, out_zip_file):
+def RenameAndUncompressLibInApk(rezip_path, in_zip_file, out_zip_file):
   rename_cmd = [
       rezip_path,
-      'inflatealign',
-      in_zip_file,
-      out_zip_file,
-    ]
-  build_utils.CheckOutput(rename_cmd)
-
-
-def DropDataDescriptorsInApk(rezip_path, in_zip_file, out_zip_file):
-  rename_cmd = [
-      rezip_path,
-      'dropdescriptors',
+      'renameinflate',
       in_zip_file,
       out_zip_file,
     ]
@@ -72,6 +78,8 @@ def main():
   parser = optparse.OptionParser()
   build_utils.AddDepfileOption(parser)
 
+  parser.add_option('--rezip-apk-jar-path',
+                    help='Path to the RezipApk jar file.')
   parser.add_option('--zipalign-path', help='Path to the zipalign tool.')
   parser.add_option('--rezip-path', help='Path to the rezip executable.')
   parser.add_option('--unsigned-apk-path', help='Path to input unsigned APK.')
@@ -90,41 +98,38 @@ def main():
 
   with tempfile.NamedTemporaryFile() as signed_apk_path_tmp, \
       tempfile.NamedTemporaryFile() as apk_to_sign_tmp, \
-      tempfile.NamedTemporaryFile() as apk_without_descriptors_tmp, \
-      tempfile.NamedTemporaryFile() as aligned_apk_tmp:
+      tempfile.NamedTemporaryFile() as uncompress_lib_apk_tmp:
 
     if options.load_library_from_zip_file:
       # We alter the name of the library so that the Android Package Manager
       # does not extract it into a separate file. This must be done before
-      # signing, as the filename is part of the signed manifest.
+      # signing, as the filename is part of the signed manifest. At the same
+      # time we uncompress the library, which is necessary so that it can be
+      # loaded directly from the APK.
+      uncompress_lib_apk_path = uncompress_lib_apk_tmp.name
+      RenameAndUncompressLibInApk(
+          options.rezip_path, options.unsigned_apk_path,
+          uncompress_lib_apk_path)
       apk_to_sign = apk_to_sign_tmp.name
-      RenameLibInApk(options.rezip_path, options.unsigned_apk_path, apk_to_sign)
+      # Move the library to a page boundary by adding a page alignment file.
+      AddPageAlignment(
+          options.rezip_apk_jar_path, uncompress_lib_apk_path, apk_to_sign)
     else:
       apk_to_sign = options.unsigned_apk_path
 
     signed_apk_path = signed_apk_path_tmp.name
-    SignApk(options.key_path, options.key_name, options.key_passwd,
-            apk_to_sign, signed_apk_path)
+    JarSigner(options.key_path, options.key_name, options.key_passwd,
+              apk_to_sign, signed_apk_path)
 
     if options.load_library_from_zip_file:
-      # Signing adds data descriptors to the APK. These are redundant
-      # information. We remove them as otherwise they can cause a
-      # miscalculation in the page alignment.
-      apk_to_align = apk_without_descriptors_tmp.name
-      DropDataDescriptorsInApk(
-          options.rezip_path, signed_apk_path, apk_to_align)
-      aligned_apk = aligned_apk_tmp.name
+      # Reorder the contents of the APK. This re-establishes the canonical
+      # order which means the library will be back at its page aligned location.
+      # This step also aligns uncompressed items to 4 bytes.
+      ReorderAndAlignApk(
+          options.rezip_apk_jar_path, signed_apk_path, options.final_apk_path)
     else:
-      apk_to_align = signed_apk_path
-      aligned_apk = options.final_apk_path
-
-    # Align uncompress items to 4 bytes
-    AlignApk(options.zipalign_path, apk_to_align, aligned_apk)
-
-    if options.load_library_from_zip_file:
-      # Uncompress the library and make sure that it is page aligned.
-      UncompressLibAndPageAlignInApk(
-          options.rezip_path, aligned_apk, options.final_apk_path)
+      # Align uncompressed items to 4 bytes
+      AlignApk(options.zipalign_path, signed_apk_path, options.final_apk_path)
 
   if options.depfile:
     build_utils.WriteDepfile(