Gin: Make it easier to implement Wrappable

gin/function_template.h.pump

Index: gin/function_template.h.pump
diff --git a/gin/function_template.h.pump b/gin/function_template.h.pump
index 23941c08287209c8eb03c2d8d92d5e6c0a57d8b0..66c226318be903b93e78120936b1a53c88b74e77 100644
--- a/gin/function_template.h.pump
+++ b/gin/function_template.h.pump
@@ -58,12 +58,12 @@ struct CallbackParamTraits<const T*> {
 // It inherits from Wrappable, which delete itself when both (a) the refcount
 // via base::RefCounted has dropped to zero, and (b) there are no more
 // JavaScript references in V8.
-class CallbackHolderBase : public Wrappable {
- public:
-  virtual WrapperInfo* GetWrapperInfo() OVERRIDE;
-  static WrapperInfo kWrapperInfo;
+
+// This simple base class is used so that we can share a single object template
+// among every CallbackHolder instance.
+class CallbackHolderBase : public Wrappable<CallbackHolderBase> {
  protected:
-  virtual ~CallbackHolderBase() {}
+  ~CallbackHolderBase() {}
 };
 
 template<typename Sig>
@@ -74,7 +74,7 @@ class CallbackHolder : public CallbackHolderBase {
   base::Callback<Sig> callback;
   int flags;
  private:
-  virtual ~CallbackHolder() {}
+  ~CallbackHolder() {}
 };