Revert^2: "Make sigchain actually own the signal chain.""

This reverts commit 33dca562d5ed9f52f63ced2334c066333ca073e9.

Bug: http://b/36205469
Bug: http://b/36262089
Original-Change-Id: I416b13de800d3e23424cf20688ccfd7e4e48a111
Change-Id: I1267be72c32ed73d1079a572d0b8907556526dde
diff --git a/sigchainlib/version-script64.txt b/sigchainlib/version-script64.txt
index 08c312e..319d1c6 100644
--- a/sigchainlib/version-script64.txt
+++ b/sigchainlib/version-script64.txt
@@ -1,11 +1,9 @@
 {
 global:
-  ClaimSignalChain;
-  UnclaimSignalChain;
-  InvokeUserSignalHandler;
   InitializeSignalChain;
   EnsureFrontOfChain;
-  SetSpecialSignalHandlerFn;
+  AddSpecialSignalHandlerFn;
+  RemoveSpecialSignalHandlerFn;
   sigaction;
   signal;
   sigprocmask;