diff -r 429bb572ee65 -r 4904bded9702 src/share/vm/runtime/thread.hpp
--- a/src/share/vm/runtime/thread.hpp	Thu Jan 30 00:21:06 2020 +0000
+++ b/src/share/vm/runtime/thread.hpp	Tue Feb 04 11:16:27 2020 +0800
@@ -734,8 +734,6 @@
 
   static bool _startable;
   volatile static bool _should_terminate; // updated without holding lock
-
-  os::WatcherThreadCrashProtection* _crash_protection;
  public:
   enum SomeConstants {
     delay_interval = 10                          // interrupt delay in milliseconds
@@ -762,15 +760,6 @@
   // Only allow start once the VM is sufficiently initialized
   // Otherwise the first task to enroll will trigger the start
   static void make_startable();
-
-  void set_crash_protection(os::WatcherThreadCrashProtection* crash_protection) {
-    assert(Thread::current()->is_Watcher_thread(), "Can only be set by WatcherThread");
-    _crash_protection = crash_protection;
-  }
-
-  bool has_crash_protection() const { return _crash_protection != NULL; }
-  os::WatcherThreadCrashProtection* crash_protection() const { return _crash_protection; }
-
  private:
   int sleep() const;
 };