Add a new GetInstance() method for singleton classes, take 2.

ceee/ie/plugin/bho/cookie_accountant.h

Index: ceee/ie/plugin/bho/cookie_accountant.h
diff --git a/ceee/ie/plugin/bho/cookie_accountant.h b/ceee/ie/plugin/bho/cookie_accountant.h
index 8e7423bd74f4916f05a31c1a61aa8883dac27187..a2b9de309bd195c65b397ff859dbd7b405a48855 100644
--- a/ceee/ie/plugin/bho/cookie_accountant.h
+++ b/ceee/ie/plugin/bho/cookie_accountant.h
@@ -125,8 +125,10 @@ class CookieAccountant {
 // A singleton that initializes and keeps the CookieAccountant used by
 // production code. This class is separate so that CookieAccountant can still
 // be accessed for unit testing.
-class ProductionCookieAccountant : public CookieAccountant,
-    public Singleton<ProductionCookieAccountant> {
+class ProductionCookieAccountant : public CookieAccountant {
+ public:
+  static ProductionCookieAccountant* GetInstance();
+
  private:
   // This ensures no construction is possible outside of the class itself.
   friend struct DefaultSingletonTraits<ProductionCookieAccountant>;