Put V8 extras into the snapshot

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 365 matching lines @@
       HandleScope handle_scope(isolate);
       Local<Context> new_context = Context::New(isolate);
       context.Reset(isolate, new_context);
       if (custom_source != NULL) {
         metadata.set_embeds_script(true);
         Context::Scope context_scope(new_context);
         if (!RunExtraCode(isolate, new_context, custom_source)) context.Reset();
       }
     }
     if (!context.IsEmpty()) {
-      // Make sure all builtin scripts are cached.
       {
         HandleScope scope(isolate);
+
+        // Make sure all builtin scripts are cached.
         for (int i = 0; i < i::Natives::GetBuiltinsCount(); i++) {
           internal_isolate->bootstrapper()->SourceLookup<i::Natives>(i);
         }
+
+        // Make sure all extra scripts are cached.
+        for (int i = 0; i < i::ExtraNatives::GetBuiltinsCount(); i++) {
+          internal_isolate->bootstrapper()->SourceLookup<i::ExtraNatives>(i);
+        }

[Yang, 2015/08/13 12:28:24]

I don't think any of this is actually necessary. What happens if you remove this
and the loop above for Natives?

       }
       // If we don't do this then we end up with a stray root pointing at the
       // context even after we have disposed of the context.
       internal_isolate->heap()->CollectAllAvailableGarbage("mksnapshot");
       i::Object* raw_context = *v8::Utils::OpenPersistent(context);
       context.Reset();
 
       i::SnapshotByteSink snapshot_sink;
       i::StartupSerializer ser(internal_isolate, &snapshot_sink);
       ser.SerializeStrongReferences();
@@ skipping 8016 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8