Revert of Revert of [Android] JUnit runner + gyp changes.

build/android/gyp/javac.py

 #!/usr/bin/env python
 #
 # 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 optparse
 import os
 import shutil
 import re
 import sys
+import textwrap
 
 from util import build_utils
 from util import md5_check
 
 import jar
 
 sys.path.append(build_utils.COLORAMA_ROOT)
 import colorama
 
 
@@ skipping 76 matching lines @@
         stderr_filter=ColorJavacOutput)
 
   record_path = os.path.join(classes_dir, 'javac.md5.stamp')
   md5_check.CallAndRecordIfStale(
       Compile,
       record_path=record_path,
       input_paths=java_files + jar_inputs,
       input_strings=javac_cmd)
 
 
+_MAX_MANIFEST_LINE_LEN = 72
+
+
+def CreateManifest(manifest_path, classpath, main_class=None):
+  """Creates a manifest file with the given parameters.
+
+  This generates a manifest file that compiles with the spec found at
+  http://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html#JAR_Manifest
+
+  Args:
+    manifest_path: The path to the manifest file that should be created.
+    classpath: The JAR files that should be listed on the manifest file's
+      classpath.
+    main_class: If present, the class containing the main() function.
+
+  """
+  output = ['Manifest-Version: 1.0']
+  if main_class:
+    output.append('Main-Class: %s' % main_class)
+  if classpath:
+    sanitized_paths = []
+    for path in classpath:
+      sanitized_paths.append(os.path.basename(path.strip('"')))
+    output.append('Class-Path: %s' % ' '.join(sanitized_paths))
+  output.append('Created-By: ')
+  output.append('')
+
+  wrapper = textwrap.TextWrapper(break_long_words=True,
+                                 drop_whitespace=False,
+                                 subsequent_indent=' ',
+                                 width=_MAX_MANIFEST_LINE_LEN - 2)
+  output = '\r\n'.join(w for l in output for w in wrapper.wrap(l))
+
+  with open(manifest_path, 'w') as f:
+    f.write(output)
+
+
 def main(argv):
   colorama.init()
 
   argv = build_utils.ExpandFileArgs(argv)
 
   parser = optparse.OptionParser()
   build_utils.AddDepfileOption(parser)
 
   parser.add_option(
       '--src-gendirs',
@@ skipping 20 matching lines @@
   parser.add_option(
       '--chromium-code',
       type='int',
       help='Whether code being compiled should be built with stricter '
       'warnings for chromium code.')
 
   parser.add_option(
       '--classes-dir',
       help='Directory for compiled .class files.')
   parser.add_option('--jar-path', help='Jar output path.')
+  parser.add_option(
+      '--main-class',
+      help='The class containing the main method.')
 
   parser.add_option('--stamp', help='Path to touch on success.')
 
   options, args = parser.parse_args(argv)
 
+  if options.main_class and not options.jar_path:
+    parser.error('--main-class requires --jar-path')
+
   classpath = []
   for arg in options.classpath:
     classpath += build_utils.ParseGypList(arg)
 
   java_srcjars = []
   for arg in options.java_srcjars:
     java_srcjars += build_utils.ParseGypList(arg)
 
   java_files = args
   if options.src_gendirs:
@@ skipping 21 matching lines @@
             break
       java_files = filtered_java_files
 
     DoJavac(
         classpath,
         classes_dir,
         options.chromium_code,
         java_files)
 
     if options.jar_path:
+      if options.main_class:
+        manifest_file = os.path.join(temp_dir, 'manifest')
+        CreateManifest(manifest_file, classpath,
+                       options.main_class)
+      else:
+        manifest_file = None
       jar.JarDirectory(classes_dir,
                        build_utils.ParseGypList(options.jar_excluded_classes),
-                       options.jar_path)
+                       options.jar_path,
+                       manifest_file=manifest_file)
 
     if options.classes_dir:
       # Delete the old classes directory. This ensures that all .class files in
       # the output are actually from the input .java files. For example, if a
       # .java file is deleted or an inner class is removed, the classes
       # directory should not contain the corresponding old .class file after
       # running this action.
       build_utils.DeleteDirectory(options.classes_dir)
       shutil.copytree(classes_dir, options.classes_dir)
 
   if options.depfile:
     build_utils.WriteDepfile(
         options.depfile,
         input_files + build_utils.GetPythonDependencies())
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))