Update from https://crrev.com/320343

base/tracked_objects.h

 // 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.
 
 #ifndef BASE_TRACKED_OBJECTS_H_
 #define BASE_TRACKED_OBJECTS_H_
 
 #include <map>
 #include <set>
 #include <stack>
@@ skipping 222 matching lines @@
 
 class BASE_EXPORT Births: public BirthOnThread {
  public:
   Births(const Location& location, const ThreadData& current);
 
   int birth_count() const;
 
   // When we have a birth we update the count for this birthplace.
   void RecordBirth();
 
-  // When a birthplace is changed (updated), we need to decrement the counter
-  // for the old instance.
-  void ForgetBirth();
-
-  // Hack to quickly reset all counts to zero.
-  void Clear();
-
  private:
   // The number of births on this thread for our location_.
   int birth_count_;
 
   DISALLOW_COPY_AND_ASSIGN(Births);
 };
 
 //------------------------------------------------------------------------------
 // Basic info summarizing multiple destructions of a tracked object with a
 // single birthplace (fixed Location).  Used both on specific threads, and also
@@ skipping 17 matching lines @@
 
   // Metrics accessors, used only for serialization and in tests.
   int count() const;
   int32 run_duration_sum() const;
   int32 run_duration_max() const;
   int32 run_duration_sample() const;
   int32 queue_duration_sum() const;
   int32 queue_duration_max() const;
   int32 queue_duration_sample() const;
 
-  // Reset the max values to zero.
-  void ResetMax();
-
   // Reset all tallies to zero. This is used as a hack on realtime data.
   void Clear();
 
  private:
   // Members are ordered from most regularly read and updated, to least
   // frequently used.  This might help a bit with cache lines.
   // Number of runs seen (divisor for calculating averages).
   int count_;
   // Basic tallies, used to compute averages.
   int32 run_duration_sum_;
@@ skipping 79 matching lines @@
   // only used by the message loop, which has a well defined thread name.
   static void InitializeThreadContext(const std::string& suggested_name);
 
   // Using Thread Local Store, find the current instance for collecting data.
   // If an instance does not exist, construct one (and remember it for use on
   // this thread.
   // This may return NULL if the system is disabled for any reason.
   static ThreadData* Get();
 
   // Fills |process_data| with all the recursive results in our process.
-  // During the scavenging, if |reset_max| is true, then the DeathData instances
-  // max-values are reset to zero during this scan.
-  static void Snapshot(bool reset_max, ProcessDataSnapshot* process_data);
+  static void Snapshot(ProcessDataSnapshot* process_data);
 
   // Finds (or creates) a place to count births from the given location in this
   // thread, and increment that tally.
   // TallyABirthIfActive will returns NULL if the birth cannot be tallied.
   static Births* TallyABirthIfActive(const Location& location);
 
   // Records the end of a timed run of an object.  The |completed_task| contains
   // a pointer to a Births, the time_posted, and a delayed_start_time if any.
   // The |start_of_run| indicates when we started to perform the run of the
   // task.  The delayed_start_time is non-null for tasks that were posted as
@@ skipping 18 matching lines @@
       const TaskStopwatch& stopwatch);
 
   // Record the end of execution in region, generally corresponding to a scope
   // being exited.
   static void TallyRunInAScopedRegionIfTracking(
       const Births* birth,
       const TaskStopwatch& stopwatch);
 
   const std::string& thread_name() const { return thread_name_; }
 
-  // Hack: asynchronously clear all birth counts and death tallies data values
-  // in all ThreadData instances.  The numerical (zeroing) part is done without
-  // use of a locks or atomics exchanges, and may (for int64 values) produce
-  // bogus counts VERY rarely.
-  static void ResetAllThreadData();
-
   // Initializes all statics if needed (this initialization call should be made
   // while we are single threaded). Returns false if unable to initialize.
   static bool Initialize();
 
   // Sets internal status_.
   // If |status| is false, then status_ is set to DEACTIVATED.
   // If |status| is true, then status_ is set to, PROFILING_ACTIVE, or
   // PROFILING_CHILDREN_ACTIVE.
   // If tracking is not compiled in, this function will return false.
   // If parent-child tracking is not compiled in, then an attempt to set the
@@ skipping 77 matching lines @@
   // In this thread's data, record a new birth.
   Births* TallyABirth(const Location& location);
 
   // Find a place to record a death on this thread.
   void TallyADeath(const Births& birth,
                    int32 queue_duration,
                    const TaskStopwatch& stopwatch);
 
   // Snapshot (under a lock) the profiled data for the tasks in each ThreadData
   // instance.  Also updates the |birth_counts| tally for each task to keep
-  // track of the number of living instances of the task.  If |reset_max| is
-  // true, then the max values in each DeathData instance are reset during the
-  // scan.
-  static void SnapshotAllExecutedTasks(bool reset_max,
-                                       ProcessDataSnapshot* process_data,
+  // track of the number of living instances of the task.
+  static void SnapshotAllExecutedTasks(ProcessDataSnapshot* process_data,
                                        BirthCountMap* birth_counts);
 
   // Snapshots (under a lock) the profiled data for the tasks for this thread
   // and writes all of the executed tasks' data -- i.e. the data for the tasks
   // with with entries in the death_map_ -- into |process_data|.  Also updates
   // the |birth_counts| tally for each task to keep track of the number of
   // living instances of the task -- that is, each task maps to the number of
-  // births for the task that have not yet been balanced by a death.  If
-  // |reset_max| is true, then the max values in each DeathData instance are
-  // reset during the scan.
-  void SnapshotExecutedTasks(bool reset_max,
-                             ProcessDataSnapshot* process_data,
+  // births for the task that have not yet been balanced by a death.
+  void SnapshotExecutedTasks(ProcessDataSnapshot* process_data,
                              BirthCountMap* birth_counts);
 
   // Using our lock, make a copy of the specified maps.  This call may be made
   // on  non-local threads, which necessitate the use of the lock to prevent
-  // the map(s) from being reallocated while they are copied. If |reset_max| is
-  // true, then, just after we copy the DeathMap, we will set the max values to
-  // zero in the active DeathMap (not the snapshot).
-  void SnapshotMaps(bool reset_max,
-                    BirthMap* birth_map,
+  // the map(s) from being reallocated while they are copied.
+  void SnapshotMaps(BirthMap* birth_map,
                     DeathMap* death_map,
                     ParentChildSet* parent_child_set);
 
-  // Using our lock to protect the iteration, Clear all birth and death data.
-  void Reset();
-
   // This method is called by the TLS system when a thread terminates.
   // The argument may be NULL if this thread has never tracked a birth or death.
   static void OnThreadTermination(void* thread_data);
 
   // This method should be called when a worker thread terminates, so that we
   // can save all the thread data into a cache of reusable ThreadData instances.
   void OnThreadTerminationCleanup();
 
   // Cleans up data structures, and returns statics to near pristine (mostly
   // uninitialized) state.  If there is any chance that other threads are still
@@ skipping 209 matching lines @@
   ~ProcessDataSnapshot();
 
   std::vector<TaskSnapshot> tasks;
   std::vector<ParentChildPairSnapshot> descendants;
   int process_id;
 };
 
 }  // namespace tracked_objects
 
 #endif  // BASE_TRACKED_OBJECTS_H_