Add a --unmanaged flag to gclient config to allow the main solution to be unmanaged by the scm.

gclient_scm.py

Index: gclient_scm.py
===================================================================
--- gclient_scm.py	(revision 98571)
+++ gclient_scm.py	(working copy)
@@ -174,9 +174,13 @@
     url, deps_revision = gclient_utils.SplitUrlRevision(self.url)
     rev_str = ""
     revision = deps_revision
+    managed = True
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
+      if revision == 'unmanaged':
+        revision = None
+        managed = False
     if not revision:
       revision = default_rev
 
@@ -218,6 +222,10 @@
         print('')
       return
 
+    if not managed:
+      print ('________ unmanaged solution; skipping %s' % self.relpath)
+      return
+
     if not os.path.exists(os.path.join(self.checkout_path, '.git')):
       raise gclient_utils.Error('\n____ %s%s\n'
                                 '\tPath is not a git repo. No .git dir.\n'
@@ -735,14 +743,19 @@
     url, revision = gclient_utils.SplitUrlRevision(self.url)
     # Keep the original unpinned url for reference in case the repo is switched.
     base_url = url
+    managed = True
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
     if revision:
-      forced_revision = True
-      # Reconstruct the url.
-      url = '%s@%s' % (url, revision)
-      rev_str = ' at %s' % revision
+      if revision != 'unmanaged':
+        forced_revision = True
+        # Reconstruct the url.
+        url = '%s@%s' % (url, revision)
+        rev_str = ' at %s' % revision
+      else:
+        managed = False
+        revision = None
     else:
       forced_revision = False
       rev_str = ''
@@ -754,6 +767,10 @@
       self._RunAndGetFileList(command, options, file_list, self._root_dir)
       return
 
+    if not managed:
+      print ('________ unmanaged solution; skipping %s' % self.relpath)
+      return
+
     # Get the existing scm url and the revision number of the current checkout.
     try:
       from_info = scm.SVN.CaptureInfo(os.path.join(self.checkout_path, '.'))