Reland 66791 (change was innocent)...

base/thread_restrictions.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/thread_restrictions.h"
 
 // This entire file is compiled out in Release mode.
 #ifndef NDEBUG
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/thread_local.h"
 
 namespace base {
 
 namespace {
 
 LazyInstance<ThreadLocalBoolean, LeakyLazyInstanceTraits<ThreadLocalBoolean> >
     g_io_disallowed(LINKER_INITIALIZED);
 
+LazyInstance<ThreadLocalBoolean, LeakyLazyInstanceTraits<ThreadLocalBoolean> >
+    g_singleton_disallowed(LINKER_INITIALIZED);
+
 }  // anonymous namespace
 
 // static
 bool ThreadRestrictions::SetIOAllowed(bool allowed) {
-  bool previous_allowed = g_io_disallowed.Get().Get();
+  bool previous_disallowed = g_io_disallowed.Get().Get();
   g_io_disallowed.Get().Set(!allowed);
-  return !previous_allowed;
+  return !previous_disallowed;
 }
 
 // static
 void ThreadRestrictions::AssertIOAllowed() {
   if (g_io_disallowed.Get().Get()) {
     LOG(FATAL) <<
         "Function marked as IO-only was called from a thread that "
         "disallows IO!  If this thread really should be allowed to "
         "make IO calls, adjust the call to "
         "base::ThreadRestrictions::SetIOAllowed() in this thread's "
         "startup.";
   }
 }
 
+bool ThreadRestrictions::SetSingletonAllowed(bool allowed) {
+  bool previous_disallowed = g_singleton_disallowed.Get().Get();
+  g_singleton_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+// static
+void ThreadRestrictions::AssertSingletonAllowed() {
+  if (g_singleton_disallowed.Get().Get()) {
+    LOG(FATAL) << "LazyInstance/Singleton is not allowed to be used on this "
+               << "thread.  Most likely it's because this thread is not "
+               << "joinable, so AtExitManager may have deleted the object "
+               << "on shutdown, leading to a potential shutdown crash.";
+  }
+}
+
 }  // namespace base
 
 #endif  // NDEBUG