gclient: update git-cl whenever git-cl is run and not when gclient is run

Rather than updating git-cl whenever gclient is invoked, update it
whenever git-cl is invoked.

In the chromium-os workflow, folks often run git-cl but rarely run gclient.
This results in folks running an older git-cl which may not
have the latest features/fixes.

TEST=

Tested that git-cl is updated when it is stale, git-cl is cloned when it doesn't exist and is not updated when DEPOT_TOOLS_UPDATE=0

Review URL: http://codereview.chromium.org/2962013

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@52236 0039d316-1c4b-4281-b951-d872f2087c98

gclient

@@ -52,12 +52,6 @@ then
   cd - > /dev/null
 fi
 
-if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/git-cl-repo/.git" ]
-then
-  test_git
-  (cd "$base_dir/git-cl-repo"; git pull -q)
-fi
-
 # Use the batch file as an entry point if on cygwin.
 if [ "${OSTYPE}" = "cygwin" -a "${TERM}" != "xterm" ]; then
    ${base_dir}/gclient.bat "$@"

git-cl

@@ -26,6 +26,10 @@ fi
 
 if [ ! -f "$repo/git-cl" ]; then
   git clone $url $repo -q
+elif [ ! -e "$base_dir/git-cl-repo/.git" ]; then
+  echo "$0: $base_dir/git-cl-repo does not appear to be a git repo"
+elif [ "X$DEPOT_TOOLS_UPDATE" != "X0" ]; then
+  (cd "$base_dir/git-cl-repo"; git pull -q)
 fi
 
 $repo/git-cl "$@"