Use macros to define pepper interfaces

ppapi/proxy/ppb_core_proxy.h

Index: ppapi/proxy/ppb_core_proxy.h
diff --git a/ppapi/proxy/ppb_core_proxy.h b/ppapi/proxy/ppb_core_proxy.h
index 1963e718cde7ed9a8de4aa781b417c90ba799349..950e5e822adfa868eb810dbec2f52cd8111b38f2 100644
--- a/ppapi/proxy/ppb_core_proxy.h
+++ b/ppapi/proxy/ppb_core_proxy.h
@@ -8,6 +8,7 @@
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_var.h"
+#include "ppapi/c/ppb_core.h"
 #include "ppapi/proxy/interface_proxy.h"
 #include "ppapi/shared_impl/host_resource.h"
 
@@ -18,22 +19,25 @@ namespace proxy {
 
 class PPB_Core_Proxy : public InterfaceProxy {
  public:
-  PPB_Core_Proxy(Dispatcher* dispatcher, const void* target_interface);
+  PPB_Core_Proxy(Dispatcher* dispatcher);
   virtual ~PPB_Core_Proxy();
 
-  static const Info* GetInfo();
-
-  const PPB_Core* ppb_core_target() const {
-    return reinterpret_cast<const PPB_Core*>(target_interface());
-  }
+  static const PPB_Core* GetPPB_Core_Interface();
 
   // InterfaceProxy implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
+  static const InterfaceID kInterfaceID = INTERFACE_ID_PPB_CORE;
+
  private:
   // Message handlers.
   void OnMsgAddRefResource(const ppapi::HostResource& resource);
   void OnMsgReleaseResource(const ppapi::HostResource& resource);
+
+  // When this proxy is in the host side, this value caches the interface
+  // pointer so we don't have to retrieve it from the dispatcher each time.
+  // In the plugin, this value is always NULL.
+  const PPB_Core* ppb_core_impl_;
 };
 
 }  // namespace proxy