Make grit resource maps work also for strings

grit/format/resource_map.py

Index: grit/format/resource_map.py
diff --git a/grit/format/resource_map.py b/grit/format/resource_map.py
index 90370aa20eb09b0e894294172cadd90a824a6575..b5a7b453855ab5e57c210fb0628f7574c65936da 100644
--- a/grit/format/resource_map.py
+++ b/grit/format/resource_map.py
@@ -104,17 +104,23 @@ const size_t %(map_name)sSize = arraysize(%(map_name)s);
 
 def _FormatSource(get_key, root, lang, output_dir):
   from grit.format import rc_header
-  from grit.node import include, structure
+  from grit.node import include, structure, message
   yield _FormatSourceHeader(root)
   tids = rc_header.GetIds(root)
   seen = set()
+  active_descendants = [item for item in root.ActiveDescendants()]
   for item in root:
-    if isinstance(item, (include.IncludeNode, structure.StructureNode)):
+    if isinstance(item, (include.IncludeNode,
+                         structure.StructureNode,
+                         message.MessageNode)):
       key = get_key(item)
       tid = item.attrs['name']
       if tid in tids and key not in seen:
         seen.add(key)
-        yield '  {"%s", %s},\n' % (key, tid)
+        # For messages, only include the active ones
+        if not isinstance(item, message.MessageNode) \
+            or item in active_descendants:
+          yield '  {"%s", %s},\n' % (key, tid)
   yield _FormatSourceFooter(root)