Update AssertSingletonAllowed log message to reflect new restrictions w.r.t. CONTINUE_ON_SHUTDOWN t…

base/threading/thread_restrictions.cc

 // Copyright (c) 2012 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/threading/thread_restrictions.h"
 
 #if ENABLE_THREAD_RESTRICTIONS
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 38 matching lines @@
   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.";
+               << "joinable (or the current task is running with "
+               << "TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN semantics), so "
+               << "AtExitManager may have deleted the object on shutdown, "
+               << "leading to a potential shutdown crash. If you need to use "
+               << "the object from this context, it'll have to be updated to "
+               << "use Leaky traits.";
   }
 }
 
 // static
 void ThreadRestrictions::DisallowWaiting() {
   g_wait_disallowed.Get().Set(true);
 }
 
 // static
 void ThreadRestrictions::AssertWaitAllowed() {
   if (g_wait_disallowed.Get().Get()) {
     LOG(FATAL) << "Waiting is not allowed to be used on this thread to prevent "
                << "jank and deadlock.";
   }
 }
 
 bool ThreadRestrictions::SetWaitAllowed(bool allowed) {
   bool previous_disallowed = g_wait_disallowed.Get().Get();
   g_wait_disallowed.Get().Set(!allowed);
   return !previous_disallowed;
 }
 
 }  // namespace base
 
 #endif  // ENABLE_THREAD_RESTRICTIONS