In preparation for becoming an internal plugin in chrome I did these things:...

plugin/cross/config_common.cc

Index: plugin/cross/config_common.cc
===================================================================
--- plugin/cross/config_common.cc	(revision 20106)
+++ plugin/cross/config_common.cc	(working copy)
@@ -52,6 +52,8 @@
 
 using glue::_o3d::GetServiceLocator;
 
+namespace o3d {
+
 // Gets the value of "navigator.userAgent" in the JavaScript context, which
 // contains the user agent string.
 std::string GetUserAgent(NPP npp) {
@@ -213,3 +215,4 @@
   if (!CheckUserAgent(npp, user_agent)) return false;
   return true;
 }
+}  // namespace o3d