Merge initial implementation of deferred handling in the VM:

runtime/vm/raw_object_snapshot.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bigint_operations.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/symbols.h"
 #include "vm/visitor.h"
@@ skipping 1076 matching lines @@
   // Allocate library prefix object.
   LibraryPrefix& prefix = LibraryPrefix::ZoneHandle(
       reader->isolate(), NEW_OBJECT(LibraryPrefix));
   reader->AddBackRef(object_id, &prefix, kIsDeserialized);
 
   // Set the object tags.
   prefix.set_tags(tags);
 
   // Set all non object fields.
   prefix.raw_ptr()->num_imports_ = reader->ReadIntptrValue();
+  prefix.raw_ptr()->is_deferred_load_ = reader->Read<bool>();
+  prefix.raw_ptr()->is_loaded_ = reader->Read<bool>();
 
   // Set all the object fields.
   // TODO(5411462): Need to assert No GC can happen here, even though
   // allocations may happen.
   intptr_t num_flds = (prefix.raw()->to() - prefix.raw()->from());
   for (intptr_t i = 0; i <= num_flds; i++) {
     *(prefix.raw()->from() + i) = reader->ReadObjectRef();
   }
 
   return prefix.raw();
 }
 
 
 void RawLibraryPrefix::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT(((kind == Snapshot::kScript) &&
           !RawObject::IsCreatedFromSnapshot(writer->GetObjectTags(this))) ||
          (kind == Snapshot::kFull));
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
-  writer->WriteVMIsolateObject(kLibraryPrefixCid);
+  writer->WriteIndexedObject(kLibraryPrefixCid);
   writer->WriteIntptrValue(writer->GetObjectTags(this));
 
   // Write out all non object fields.
   writer->WriteIntptrValue(ptr()->num_imports_);
+  writer->Write<bool>(ptr()->is_deferred_load_);
+  writer->Write<bool>(ptr()->is_loaded_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawNamespace* Namespace::ReadFrom(SnapshotReader* reader,
                                   intptr_t object_id,
                                   intptr_t tags,
@@ skipping 1538 matching lines @@
     // We do not allow objects with native fields in an isolate message.
     writer->SetWriteException(Exceptions::kArgument,
                               "Illegal argument in isolate message"
                               " : (object is a MirrorReference)");
   } else {
     UNREACHABLE();
   }
 }
 
 }  // namespace dart