Use macros to define pepper interfaces

ppapi/proxy/ppb_var_proxy.h

Index: ppapi/proxy/ppb_var_proxy.h
diff --git a/ppapi/proxy/ppb_var_proxy.h b/ppapi/proxy/ppb_var_proxy.h
index 6e060b9949908a84929e8bcf0b34a731a8e4281e..9a071d7c7cd35acaa0c012537cff03939c4a70f2 100644
--- a/ppapi/proxy/ppb_var_proxy.h
+++ b/ppapi/proxy/ppb_var_proxy.h
@@ -12,23 +12,9 @@ struct PPB_Var;
 namespace ppapi {
 namespace proxy {
 
-class PPB_Var_Proxy : public InterfaceProxy {
- public:
-  PPB_Var_Proxy(Dispatcher* dispatcher,
-                const void* target_interface);
-  virtual ~PPB_Var_Proxy();
-
-  static const Info* GetInfo();
-
-  const PPB_Var* ppb_var_target() const {
-    return static_cast<const PPB_Var*>(target_interface());
-  }
-
-  // InterfaceProxy implementation. In this case, no messages are sent or
-  // received, so this always returns false.
-  virtual bool OnMessageReceived(const IPC::Message& msg);
-
-};
+// Returns a pointer to the plugin-specific implementation of PPB_Var.
+// There is no proxy object since this is implemented entirely in-process.
+const PPB_Var* GetPPB_Var_Interface();
 
 }  // namespace proxy
 }  // namespace ppapi