Support large objects in the serializer/deserializer.

src/mksnapshot.cc

Index: src/mksnapshot.cc
diff --git a/src/mksnapshot.cc b/src/mksnapshot.cc
index b4a40180a5081e1451338fe404cc798c216d21de..2e2ff6cd268176a25ee38bec4be26b6d8ff9aeae 100644
--- a/src/mksnapshot.cc
+++ b/src/mksnapshot.cc
@@ -67,6 +67,11 @@ class SnapshotWriter {
                      const i::Serializer& serializer,
                      const i::List<i::byte>& context_snapshot_data,
                      const i::Serializer& context_serializer) const {
+    // The serializer supports large objects, but we don't expect any in the
+    // the startup snapshot.  If this changes, we need to write it into the
+    // snapshot file and read it for deserialization.
+    CHECK_EQ(0, serializer.large_objects_total_size());
+    CHECK_EQ(0, context_serializer.large_objects_total_size());
     WriteSnapshotFile(snapshot_data, serializer,
                       context_snapshot_data, context_serializer);
     MaybeWriteStartupBlob(snapshot_data, serializer,
@@ -84,10 +89,11 @@ class SnapshotWriter {
     i::List<i::byte> startup_blob;
     i::ListSnapshotSink sink(&startup_blob);
 
-    int spaces[] = {
-        i::NEW_SPACE, i::OLD_POINTER_SPACE, i::OLD_DATA_SPACE, i::CODE_SPACE,
-        i::MAP_SPACE, i::CELL_SPACE,  i::PROPERTY_CELL_SPACE
-    };
+    // Large object space reservation is not necessary.
+    int spaces[] = {i::NEW_SPACE,          i::OLD_POINTER_SPACE,
+                    i::OLD_DATA_SPACE,     i::CODE_SPACE,
+                    i::MAP_SPACE,          i::CELL_SPACE,
+                    i::PROPERTY_CELL_SPACE};
 
     i::byte* snapshot_bytes = snapshot_data.begin();
     sink.PutBlob(snapshot_bytes, snapshot_data.length(), "snapshot");