Return matching plug-ins in the sorted order (by version number).

content/common/plugin_list.h

Index: content/common/plugin_list.h
diff --git a/content/common/plugin_list.h b/content/common/plugin_list.h
index 1205238706bc0578553bed5f26eaf88f05bc0686..78f83fe03ea11b82c8a804fef7b47a8223387976 100644
--- a/content/common/plugin_list.h
+++ b/content/common/plugin_list.h
@@ -171,6 +171,10 @@ class CONTENT_EXPORT PluginList {
     LOADING_STATE_UP_TO_DATE,
   };
 
+  struct VersionComparator {
+    bool operator()(const WebPluginInfo& lhs, const WebPluginInfo& rhs) const;
+  };
+
   friend class PluginListTest;
   friend struct base::DefaultLazyInstanceTraits<PluginList>;