Dedupe codereview.settings parsing code. Add more testing.

gclient_utils.py

Index: gclient_utils.py
diff --git a/gclient_utils.py b/gclient_utils.py
index bad86915b332a02ce1c8cb826cdd1bbfe639c96e..1edce769a71e8dc3ad88384ee7a2c4fc22a230f8 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -732,3 +732,15 @@ def RunEditor(content, git):
     return FileRead(filename)
   finally:
     os.remove(filename)
+
+
+def ParseCodereviewSettingsContent(content):
+  """Process a codereview.settings file properly."""
+  lines = (l for l in content.splitlines() if not l.strip().startswith("#"))
+  try:
+    keyvals = dict([x.strip() for x in l.split(':', 1)] for l in lines if l)
+  except ValueError:
+    raise Error(
+        'Failed to process settings, please fix. Content:\n\n%s' % content)
+  # TODO(maruel): Post-process
+  return keyvals