Remove libsigchain from LD_PRELOADS

  Link sigchain.cc statically with dalvikvm, app_process,
  surfaceflinger, dex2oat, patchoat and objdump.

  Replace libsigchain.so with dummy implementaions to avoid
  situations when it is used incorrectly.

Bug: 15345057
Bug: 15426766
Change-Id: If0b7f59a59824e30aa0c33dad76c7a44932180de
diff --git a/sigchainlib/sigchain.h b/sigchainlib/sigchain.h
index 5bc4026..0de0d08 100644
--- a/sigchainlib/sigchain.h
+++ b/sigchainlib/sigchain.h
@@ -19,16 +19,12 @@
 
 #include <signal.h>
 
-namespace art {
+extern "C" void InitializeSignalChain();
 
-void InitializeSignalChain();
+extern "C" void ClaimSignalChain(int signal, struct sigaction* oldaction);
 
-void ClaimSignalChain(int signal, struct sigaction* oldaction);
+extern "C" void UnclaimSignalChain(int signal);
 
-void UnclaimSignalChain(int signal);
-
-void InvokeUserSignalHandler(int sig, siginfo_t* info, void* context);
-
-}   // namespace art
+extern "C" void InvokeUserSignalHandler(int sig, siginfo_t* info, void* context);
 
 #endif  // ART_SIGCHAINLIB_SIGCHAIN_H_