Rename InterfaceID to ApiID and move the file.

ppapi/thunk/enter.h

Index: ppapi/thunk/enter.h
diff --git a/ppapi/thunk/enter.h b/ppapi/thunk/enter.h
index 5504f68ad69851d1cb271a5d86f20fe2b746c9ca..5d62173c5e3405f725796ac6a733fd4e0bbe1ef6 100644
--- a/ppapi/thunk/enter.h
+++ b/ppapi/thunk/enter.h
@@ -7,7 +7,7 @@
 
 #include "base/basictypes.h"
 #include "ppapi/c/pp_resource.h"
-#include "ppapi/proxy/interface_id.h"
+#include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/function_group_base.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/proxy_lock.h"
@@ -75,7 +75,7 @@ class EnterFunction : subtle::LockOnEntry<lock_on_entry> {
   EnterFunction(PP_Instance instance, bool report_error)
       : functions_(NULL) {
     FunctionGroupBase* base = PpapiGlobals::Get()->GetFunctionAPI(
-        instance, FunctionsT::interface_id);
+        instance, FunctionsT::kApiID);
     if (base)
       functions_ = base->GetAs<FunctionsT>();
     // TODO(brettw) check error and if report_error is set, do something.