Fix reitveld base URL for googlesource.com repos.

The base url was previously being generated as
URL@BRANCH.  I'm not sure if this works anywhere
but it certainly doesn't on googlesource.com.
Here we want URL/+/BRANCH.

R=iannucci@chromium.org, sergeyberezin@chromium.org

Review URL: https://codereview.chromium.org/652193004

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@292493 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -1698,9 +1698,13 @@ def RietveldUpload(options, args, cl, change):
                     if ': ' in line)
         remote_url = keys.get('URL', None)
     else:
-      if cl.GetRemoteUrl() and '/' in cl.GetUpstreamBranch():
-        remote_url = (cl.GetRemoteUrl() + '@'
-                      + cl.GetUpstreamBranch().split('/')[-1])
+      remote = cl.GetRemoteUrl()
+      branch = cl.GetUpstreamBranch()
+      if remote and branch:
+        if 'googlesource' in remote:
+          remote_url = remote + '/+/' + branch.split('/')[-1]
+        else:
+          remote_url = remote + '@' + branch.split('/')[-1]
   if remote_url:
     upload_args.extend(['--base_url', remote_url])