[bootstrapper] extra natives must not use natives syntax.

src/extensions/externalize-string-extension.cc

Index: src/extensions/externalize-string-extension.cc
diff --git a/src/extensions/externalize-string-extension.cc b/src/extensions/externalize-string-extension.cc
index 9241e9f4de87e76abd86d739a18481528b61a569..2ed3ad27e5b405708f5d3be79f393aa3f7a402e1 100644
--- a/src/extensions/externalize-string-extension.cc
+++ b/src/extensions/externalize-string-extension.cc
@@ -36,10 +36,10 @@ typedef SimpleStringResource<char, v8::String::ExternalOneByteStringResource>
 typedef SimpleStringResource<uc16, v8::String::ExternalStringResource>
     SimpleTwoByteStringResource;
 
-
 const char* const ExternalizeStringExtension::kSource =
     "native function externalizeString();"
-    "native function isOneByteString();";
+    "native function isOneByteString();"
+    "function x() { return 1; }";
 
 v8::Local<v8::FunctionTemplate>
 ExternalizeStringExtension::GetNativeFunctionTemplate(