grit: Add fallback_to_default_layout attribute to <output>

grit/node/io.py

Index: grit/node/io.py
diff --git a/grit/node/io.py b/grit/node/io.py
index 9962bffe58797c7d49a6959cb4879a1ccaece473..69146199cb58315ab989c045add6a772e3b7d2d9 100644
--- a/grit/node/io.py
+++ b/grit/node/io.py
@@ -77,6 +77,7 @@ class OutputNode(base.Node):
       'lang' : '', # empty lang indicates all languages
       'language_section' : 'neutral', # defines a language neutral section
       'context' : '',
+      'fallback_to_default_layout' : 'true',
     }
 
   def GetType(self):
@@ -100,6 +101,9 @@ class OutputNode(base.Node):
       path = self.attrs['filename']
     return os.path.expandvars(path)
 
+  def GetFallbackToDefaultLayout(self):
+    return self.attrs['fallback_to_default_layout'].lower() == 'true'
+
   def _IsValidChild(self, child):
     return isinstance(child, EmitNode)