[snapshot] pass arguments as pointers, not references.

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 448 matching lines @@
   data->contexts_.Clear();
 
   i::SnapshotByteSink snapshot_sink;
   i::StartupSerializer startup_serializer(isolate, &snapshot_sink,
                                           function_code_handling);
   startup_serializer.SerializeStrongReferences();
 
   i::SnapshotByteSink context_sink;
   i::PartialSerializer context_serializer(isolate, &startup_serializer,
                                           &context_sink);
-  // TODO(yangguo): support multiple contexts in the snapshot.
-  DCHECK_EQ(1, contexts.length());
   context_serializer.Serialize(&contexts[0]);
   startup_serializer.SerializeWeakReferencesAndDeferred();
 
   data->created_ = true;
-  return i::Snapshot::CreateSnapshotBlob(startup_serializer,
-                                         context_serializer);
+  return i::Snapshot::CreateSnapshotBlob(&startup_serializer,
+                                         &context_serializer);
 }
 
 StartupData V8::CreateSnapshotDataBlob(const char* embedded_source) {
   // Create a new isolate and a new context from scratch, optionally run
   // a script to embed, and serialize to create a snapshot blob.
   StartupData result = {nullptr, 0};
   base::ElapsedTimer timer;
   timer.Start();
   {
     SnapshotCreator snapshot_creator;
@@ skipping 8313 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