Support external startup data in V8.

src/natives.h

Index: src/natives.h
diff --git a/src/natives.h b/src/natives.h
index 2f930dc7bdc71dcce76991c4593c9dd5c5d07973..6ddedf02cabf3fcca4c71672be36d6dbf8e30457 100644
--- a/src/natives.h
+++ b/src/natives.h
@@ -5,6 +5,10 @@
 #ifndef V8_NATIVES_H_
 #define V8_NATIVES_H_
 
+#include "src/vector.h"
+
+namespace v8 { class StartupData; }  // Forward declaration.
+
 namespace v8 {
 namespace internal {
 
@@ -39,6 +43,11 @@ class NativesCollection {
 typedef NativesCollection<CORE> Natives;
 typedef NativesCollection<EXPERIMENTAL> ExperimentalNatives;
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+// Used for reading the natives at runtime. Implementation in natives-empty.cc
+void SetNativesFromFile(StartupData* natives_blob);
+#endif
+
 } }  // namespace v8::internal
 
 #endif  // V8_NATIVES_H_