Retain original DEPS 'vars' in converted .DEPS.git.

deps2git.py

Index: deps2git.py
diff --git a/deps2git.py b/deps2git.py
index fb9145a98a155b82395512a459a7dd2aad83cc33..d40544974a4091be320a4ef4ee1fa64cf9da6e44 100755
--- a/deps2git.py
+++ b/deps2git.py
@@ -310,7 +310,7 @@ def main():
   options = parser.parse_args()[0]
 
   # Get the content of the DEPS file.
-  deps, deps_os, include_rules, skip_child_includes, hooks = (
+  deps, deps_os, include_rules, skip_child_includes, hooks, deps_vars = (
       deps_utils.GetDepsContent(options.deps))
 
   if options.extra_rules and options.type:
@@ -333,10 +333,10 @@ def main():
   # Create a var containing the Git and Webkit URL, this will make it easy for
   # people to use a mirror instead.
   git_url = 'https://chromium.googlesource.com'
-  deps_vars = {
+  deps_vars.update({
       'git_url': git_url,
       'webkit_url': git_url + '/chromium/blink.git',
-  }
+  })
 
   # Find and load svn_to_git_* modules that handle the URL mapping.
   svn_to_git_objs = [svn_to_git_public]