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

ceee/ie/broker/api_dispatcher.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Dispatcher and registry for Chrome Extension APIs.
 
 #ifndef CEEE_IE_BROKER_API_DISPATCHER_H_
 #define CEEE_IE_BROKER_API_DISPATCHER_H_
 
 #include <list>
@@ skipping 289 matching lines @@
 };
 
 // Convenience InvocationFactory implementation.
 template <class InvocationType>
 ApiDispatcher::Invocation* NewApiInvocation() {
   return new InvocationType();
 }
 
 // A singleton that initializes and keeps the ApiDispatcher used by production
 // code.
-class ProductionApiDispatcher : public ApiDispatcher,
-    public Singleton<ProductionApiDispatcher> {
+class ProductionApiDispatcher : public ApiDispatcher {
+ public:
+  static ProductionApiDispatcher* GetInstance();
+
  private:
   // This ensures no construction is possible outside of the class itself.
   friend struct DefaultSingletonTraits<ProductionApiDispatcher>;
   DISALLOW_IMPLICIT_CONSTRUCTORS(ProductionApiDispatcher);
 };
 
 // A convenience class that can be derived from by API function classes instead
 // of ApiDispatcher::Invocation. Mainly benefits ease of testing, so that we
 // can specify a mocked result object.
 template<class ResultType = ApiDispatcher::InvocationResult>
@@ skipping 74 matching lines @@
   virtual void CallRealPostError(const std::string& error) {
     InvocationBase::PostError(error);
   }
 
   scoped_ptr<ListValue> result_accumulator_;
   std::list<std::string> error_accumulator_;
 };
 
 
 #endif  // CEEE_IE_BROKER_API_DISPATCHER_H_