Remote nested retries on checkout.

Remove nested retries on checkout. Since the outer loop handles retries
specially, we want to let it exclusively handle retries. This will
prevent the inner retry loop triggering a timeout condition (rather than
a failure condition) with the outer loop.

BUG=chromium:665116
TEST=None

Change-Id: I4bf0c08b75861bf1c95060452118c314a121f9f3
Reviewed-on: https://chromium-review.googlesource.com/411397Reviewed-by: Ryan Tseng <hinoka@chromium.org>
Commit-Queue: Ryan Tseng <hinoka@chromium.org>

recipe_modules/bot_update/resources/bot_update.py

@@ -470,10 +470,10 @@ def force_revision(folder_name, revision):
     branch, revision = split_revision
 
   if revision and revision.upper() != 'HEAD':
-    git('checkout', '--force', revision, cwd=folder_name)
+    git('checkout', '--force', revision, cwd=folder_name, tries=1)
   else:
     ref = branch if branch.startswith('refs/') else 'origin/%s' % branch
-    git('checkout', '--force', ref, cwd=folder_name)
+    git('checkout', '--force', ref, cwd=folder_name, tries=1)
 
 
 def is_broken_repo_dir(repo_dir):
@@ -544,14 +544,15 @@ def git_checkout(solutions, revisions, shallow, refs, git_cache_dir):
           print 'Git repo %s appears to be broken, removing it' % sln_dir
           remove(sln_dir)
 
+        # Use "tries=1", since we retry manually in this loop.
         if not path.isdir(sln_dir):
-          git(*clone_cmd)
+          git(*clone_cmd, tries=1)
         else:
-          git('remote', 'set-url', 'origin', mirror_dir, cwd=sln_dir)
-          git('fetch', 'origin', cwd=sln_dir)
+          git('remote', 'set-url', 'origin', mirror_dir, cwd=sln_dir, tries=1)
+          git('fetch', 'origin', cwd=sln_dir, tries=1)
         for ref in refs:
           refspec = '%s:%s' % (ref, ref.lstrip('+'))
-          git('fetch', 'origin', refspec, cwd=sln_dir)
+          git('fetch', 'origin', refspec, cwd=sln_dir, tries=1)
 
         # Windows sometimes has trouble deleting files.
         # This can make git commands that rely on locks fail.