Remove the old type system for proxied resources. These were no longer being used.

ppapi/proxy/ppb_font_proxy.cc

Index: ppapi/proxy/ppb_font_proxy.cc
diff --git a/ppapi/proxy/ppb_font_proxy.cc b/ppapi/proxy/ppb_font_proxy.cc
index 4ce65431fb3065fb6d5c45961d6ecd5d3b06b0fe..9f946b992e61875ba6ce298ec9fd175e7292d1cb 100644
--- a/ppapi/proxy/ppb_font_proxy.cc
+++ b/ppapi/proxy/ppb_font_proxy.cc
@@ -118,10 +118,6 @@ ppapi::thunk::PPB_Font_API* Font::AsPPB_Font_API() {
   return this;
 }
 
-Font* Font::AsFont() {
-  return this;
-}
-
 PP_Bool Font::Describe(PP_FontDescription_Dev* description,
                        PP_FontMetrics_Dev* metrics) {
   TRACE_EVENT0("ppapi proxy", "Font::Describe");