Refactor emma_instr.py in preparation for porting EMMA GYP rules to GN

build/android/emma_instr_action.gypi

 # 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.
 
 # This file is meant to be included into an action to provide a rule that
 # instruments either java class files, or jars.
 
 {
   'variables': {
     'input_path%': '',
     'output_path%': '',
     'stamp_path%': '',
     'extra_instr_args': [
-      '--coverage-file=<(_target_name).em',
-      '--sources-file=<(_target_name)_sources.txt',
+      '--coverage-file=<(coverage_file)',
+      '--sources-list-file=<(sources_list_file)',
     ],
     'emma_jar': '<(android_sdk_root)/tools/lib/emma.jar',
     'conditions': [
       ['emma_instrument != 0', {
         'extra_instr_args': [
-          '--sources=<(java_in_dir)/src >(additional_src_dirs) >(generated_src_dirs)',
+          '--source-dirs=<(java_in_dir)/src >(additional_src_dirs) >(generated_src_dirs)',
           '--src-root=<(DEPTH)',
           '--emma-jar=<(emma_jar)',
           '--filter-string=<(emma_filter)',
         ],
         'instr_action': 'instrument_jar',
       }, {
         'instr_action': 'copy',
         'extra_instr_args': [],
       }]
     ]
   },
   'inputs': [
     '<(DEPTH)/build/android/gyp/emma_instr.py',
     '<(DEPTH)/build/android/gyp/util/build_utils.py',
     '<(DEPTH)/build/android/pylib/utils/command_option_parser.py',
   ],
   'action': [
     'python', '<(DEPTH)/build/android/gyp/emma_instr.py',
     '<(instr_action)',
     '--input-path=<(input_path)',
     '--output-path=<(output_path)',
     '--stamp=<(stamp_path)',
     '<@(extra_instr_args)',
   ]
 }