diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/base/tracked.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/chromium/src/base/tracked.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,128 @@
+// Copyright (c) 2006-2008 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.
+
+//------------------------------------------------------------------------------
+// Tracked is the base class for all tracked objects.  During construction, it
+// registers the fact that an instance was created, and at destruction time, it
+// records that event.  The instance may be tagged with a name, which is refered
+// to as its Location.  The Location is a file and line number, most
+// typically indicated where the object was constructed.  In some cases, as the
+// object's significance is refined (for example, a Task object is augmented to
+// do additonal things), its Location may be redefined to that later location.
+
+// Tracking includes (for each instance) recording the birth thread, death
+// thread, and duration of life (from construction to destruction).  All this
+// data is accumulated and filtered for review at about:objects.
+
+#ifndef BASE_TRACKED_H_
+#define BASE_TRACKED_H_
+
+#include <string>
+
+#include "base/time.h"
+
+#ifndef NDEBUG
+#ifndef TRACK_ALL_TASK_OBJECTS
+#define TRACK_ALL_TASK_OBJECTS
+#endif   // TRACK_ALL_TASK_OBJECTS
+#endif  // NDEBUG
+
+namespace tracked_objects {
+
+//------------------------------------------------------------------------------
+// Location provides basic info where of an object was constructed, or was
+// significantly brought to life.
+
+class Location {
+ public:
+  // Constructor should be called with a long-lived char*, such as __FILE__.
+  // It assumes the provided value will persist as a global constant, and it
+  // will not make a copy of it.
+  Location(const char* function_name, const char* file_name, int line_number)
+      : function_name_(function_name),
+        file_name_(file_name),
+        line_number_(line_number) { }
+
+  // Provide a default constructor for easy of debugging.
+  Location()
+      : function_name_("Unknown"),
+        file_name_("Unknown"),
+        line_number_(-1) { }
+
+  // Comparison operator for insertion into a std::map<> hash tables.
+  // All we need is *some* (any) hashing distinction.  Strings should already
+  // be unique, so we don't bother with strcmp or such.
+  // Use line number as the primary key (because it is fast, and usually gets us
+  // a difference), and then pointers as secondary keys (just to get some
+  // distinctions).
+  bool operator < (const Location& other) const {
+    if (line_number_ != other.line_number_)
+      return line_number_ < other.line_number_;
+    if (file_name_ != other.file_name_)
+      return file_name_ < other.file_name_;
+    return function_name_ < other.function_name_;
+  }
+
+  const char* function_name() const { return function_name_; }
+  const char* file_name()     const { return file_name_; }
+  int line_number()           const { return line_number_; }
+
+  void Write(bool display_filename, bool display_function_name,
+             std::string* output) const;
+
+  // Write function_name_ in HTML with '<' and '>' properly encoded.
+  void WriteFunctionName(std::string* output) const;
+
+ private:
+  const char* const function_name_;
+  const char* const file_name_;
+  const int line_number_;
+};
+
+
+//------------------------------------------------------------------------------
+// Define a macro to record the current source location.
+
+#define FROM_HERE tracked_objects::Location(__FUNCTION__, __FILE__, __LINE__)
+
+
+//------------------------------------------------------------------------------
+
+
+class Births;
+
+class Tracked {
+ public:
+  Tracked();
+  virtual ~Tracked();
+
+  // Used to record the FROM_HERE location of a caller.
+  void SetBirthPlace(const Location& from_here);
+
+  // When a task sits around a long time, such as in a timer, or object watcher,
+  // this method should be called when the task becomes active, and its
+  // significant lifetime begins (and its waiting to be woken up has passed).
+  void ResetBirthTime();
+
+  bool MissingBirthplace() const;
+
+ private:
+#ifdef TRACK_ALL_TASK_OBJECTS
+
+  // Pointer to instance were counts of objects with the same birth location
+  // (on the same thread) are stored.
+  Births* tracked_births_;
+  // The time this object was constructed.  If its life consisted of a long
+  // waiting period, and then it became active, then this value is generally
+  // reset before the object begins it active life.
+  base::Time tracked_birth_time_;
+
+#endif  // TRACK_ALL_TASK_OBJECTS
+
+  DISALLOW_COPY_AND_ASSIGN(Tracked);
+};
+
+}  // namespace tracked_objects
+
+#endif  // BASE_TRACKED_H_