Tag all tracked objects, including Tasks, with the program counter at the site of FROM_HERE.

base/debug/alias.h

+// Copyright (c) 2011 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.
+
+#ifndef BASE_DEBUG_ALIAS_H_
+#define BASE_DEBUG_ALIAS_H_
+#pragma once
+
+namespace base {
+namespace debug {
+
+// Make the optimizer think that var is aliased. This is to prevent it from
+// optimizing out variables that that would not otherwise be live at the point
+// of a potential crash.
+void Alias(const void* var);
+
+}  // namespace debug
+}  // namespace base
+
+#endif  // BASE_DEBUG_ALIAS_H_