Revert 143898 - Skip updating remotes if we already have the upstream revision.

TBR=maruel@chromium.org

BUG=none
TEST=none


Review URL: https://chromiumcodereview.appspot.com/10663019

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@143911 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -353,7 +353,6 @@ class GitWrapper(SCMWrapper):
       else:
         raise gclient_utils.Error('Invalid Upstream: %s' % upstream_branch)
 
-    if not scm.GIT.IsValidRevision(cwd=self.checkout_path, rev=revision):
     # Update the remotes first so we have all the refs.
     backoff_time = 5
     for _ in range(10):