Have fetch set up tag fetch refspecs.

R=agable@chromium.org
BUG=

Review URL: https://codereview.chromium.org/212413002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@261264 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/fetch.py b/fetch.py
index dfd0386..5d595f4 100755
--- a/fetch.py
+++ b/fetch.py
@@ -124,6 +124,9 @@
         'submodule', 'foreach',
         'git config -f $toplevel/.git/config submodule.$name.ignore all',
         cwd=wd)
+    self.run_git(
+        'config', '--add', 'remote.origin.fetch',
+        '+refs/tags/*:refs/tags/*', cwd=wd)
     self.run_git('config', 'diff.ignoreSubmodules', 'all', cwd=wd)