Revert "Gclient: Don't check if repository is clean if --force is passed in"

This reverts commit 3f0dacf095.

Reason for revert:
Is causing staged changes to be reverted.

BUG=607913
TBR=hinoka,dnj

Review URL: https://codereview.chromium.org/1983963002 .

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@300598 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -553,9 +553,7 @@ class GitWrapper(SCMWrapper):
 
     if current_type == 'detached':
       # case 0
-      if not options.force:
-        # Don't do this check if nuclear option is on.
-        self._CheckClean(rev_str)
+      self._CheckClean(rev_str)
       self._CheckDetachedHead(rev_str, options)
       if self._Capture(['rev-list', '-n', '1', 'HEAD']) == revision:
         self.Print('Up-to-date; skipping checkout.')
@@ -565,7 +563,7 @@ class GitWrapper(SCMWrapper):
         self._Checkout(
             options,
             revision,
-            force=(options.force or options.delete_unversioned_trees),
+            force=(options.force and options.delete_unversioned_trees),
             quiet=True,
         )
       if not printed_path: