cros_deps_diff: convert to commandline.ArgumentParser

BUG=None
TEST=`cros_deps_diff` still works
BUG=chromium:496565

Change-Id: Ibe5967558db74a498a28d6b306f40c02f3b6b740
Reviewed-on: https://chromium-review.googlesource.com/275180
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_deps_diff.py b/scripts/cros_deps_diff.py
index d2e4749..f56ca65 100644
--- a/scripts/cros_deps_diff.py
+++ b/scripts/cros_deps_diff.py
@@ -13,9 +13,9 @@
 from __future__ import print_function
 
 import json
-import optparse
 import os
 
+from chromite.lib import commandline
 from chromite.lib import dot_helper
 
 NORMAL_COLOR = 'black'
@@ -143,18 +143,18 @@
 
 
 def main(argv):
-  parser = optparse.OptionParser(
-      usage='usage: %prog [options] input1 input2...')
-  parser.add_option('-f', '--format', default='svg',
-                    help='Dot output format (png, svg, etc.).')
-  parser.add_option('-o', '--output-dir', default='.',
-                    help='Output directory.')
-  parser.add_option('-s', '--save-dot', action='store_true',
-                    help='Save dot files.')
-  options, inputs = parser.parse_args(argv)
+  parser = commandline.ArgumentParser(description=__doc__)
+  parser.add_argument('-f', '--format', default='svg',
+                      help='Dot output format (png, svg, etc.).')
+  parser.add_argument('-o', '--output-dir', default='.',
+                      help='Output directory.')
+  parser.add_argument('-s', '--save-dot', action='store_true',
+                      help='Save dot files.')
+  parser.add_argument('inputs', nargs='+')
+  options = parser.parse_args(argv)
 
   input_deps = []
-  for i in inputs:
+  for i in options.inputs:
     with open(i) as handle:
       input_deps.append(json.loads(handle.read()))