Re-invent page aligning libraries in APK file.

build/android/rezip.gyp

 # Copyright 2014 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.
 
 # Build the rezip build tool.
 {
   'targets': [
     {
       'target_name': 'rezip',
       'type': 'executable',
       'toolsets': [ 'host' ],
       'dependencies': [
         '<(DEPTH)/third_party/zlib/zlib.gyp:minizip',
       ],
       'include_dirs': [
         '<(DEPTH)',
       ],
       'sources': [
         'rezip/rezip.cc',
       ],
+    },
+    {
+      'target_name': 'prealign',
+      'type': 'none',
+      'variables': {
+        'java_in_dir': 'rezip',
+        'compile_stamp': '<(SHARED_INTERMEDIATE_DIR)/<(_target_name)/compile.stamp',
+        'javac_jar_path': '<(PRODUCT_DIR)/lib.java/prealign.jar',
+      },
+      'sources': [
+        '>(java_in_dir)/PrealignApk.java',
+      ],
+      'actions': [
+        {
+          'action_name': 'javac_<(_target_name)',
+          'message': 'Compiling <(_target_name) java sources',
+          'variables': {
+            'java_sources': ['>!@(find >(java_in_dir) -name "*.java")'],
+          },
+          'inputs': [
+            '<(DEPTH)/build/android/gyp/util/build_utils.py',
+            '<(DEPTH)/build/android/gyp/javac.py',
+            '>@(java_sources)',
+          ],
+          'outputs': [
+            '<(compile_stamp)',
+            '<(javac_jar_path)',
+          ],
+          'action': [
+            'python', '<(DEPTH)/build/android/gyp/javac.py',
+            '--classpath=',
+            '--classes-dir=<(SHARED_INTERMEDIATE_DIR)/<(_target_name)',
+            '--jar-path=<(javac_jar_path)',
+            '--stamp=<(compile_stamp)',
+            '>@(java_sources)',
+          ]
+        },
+      ],
     }
   ],
 }