[runtime] Replace global object link with native context link in all contexts.

src/snapshot/snapshot-common.cc

Index: src/snapshot/snapshot-common.cc
diff --git a/src/snapshot/snapshot-common.cc b/src/snapshot/snapshot-common.cc
index 0b7e11d1ec4a0f225e88d9d5a2bce331ad2cb222..55bd090f202a0b982052a17491766ac05b9f3653 100644
--- a/src/snapshot/snapshot-common.cc
+++ b/src/snapshot/snapshot-common.cc
@@ -85,7 +85,6 @@ MaybeHandle<Context> Snapshot::NewContextFromSnapshot(
   // If the snapshot does not contain a custom script, we need to update
   // the global object for exactly two contexts: the builtins context and the
   // script context that has the global "this" binding.

[Yang, 2015/11/27 12:28:20]

Also remove comment.

-  CHECK(EmbedsScript(isolate) || (*outdated_contexts_out)->length() == 2);
   if (FLAG_profile_deserialization) {
     double ms = timer.Elapsed().InMillisecondsF();
     int bytes = context_data.length();