Move MessageLoop to base namespace.

webkit/plugins/npapi/plugin_instance.h

Index: webkit/plugins/npapi/plugin_instance.h
diff --git a/webkit/plugins/npapi/plugin_instance.h b/webkit/plugins/npapi/plugin_instance.h
index 25a1da82c3650b013684e09903bae17ccfef792d..d40129f35d28958d4973f6c48ca41dbf0d2aabc7 100644
--- a/webkit/plugins/npapi/plugin_instance.h
+++ b/webkit/plugins/npapi/plugin_instance.h
@@ -23,7 +23,9 @@
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 
+namespace base {
 class MessageLoop;
+}
 
 namespace webkit {
 namespace npapi {
@@ -304,7 +306,7 @@ class PluginInstance : public base::RefCountedThreadSafe<PluginInstance> {
   gfx::Rect                                containing_window_frame_;
   NPCocoaEvent*                            currently_handled_event_;  // weak
 #endif
-  MessageLoop*                             message_loop_;
+  base::MessageLoop*                       message_loop_;
   scoped_refptr<PluginStreamUrl>           plugin_data_stream_;
 
   // This flag if true indicates that the plugin data would be passed from