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diff --git a/chromium/third_party/blink/renderer/platform/scheduler/util/thread_load_tracker.h b/chromium/third_party/blink/renderer/platform/scheduler/util/thread_load_tracker.h
new file mode 100644
index 00000000000..1cd7ee89188
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+++ b/chromium/third_party/blink/renderer/platform/scheduler/util/thread_load_tracker.h
@@ -0,0 +1,73 @@
+// Copyright 2016 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_UTIL_THREAD_LOAD_TRACKER_H_
+#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_UTIL_THREAD_LOAD_TRACKER_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "third_party/blink/renderer/platform/platform_export.h"
+
+namespace blink {
+namespace scheduler {
+
+// This class tracks thread load level, i.e. percentage of wall time spent
+// running tasks.
+// In order to avoid bias it reports load level at regular intervals.
+// Every |reporting_interval_| time units, it reports the average thread load
+// level computed using a sliding window of width |reporting_interval_|.
+class PLATFORM_EXPORT ThreadLoadTracker {
+ public:
+  // Callback is called with (current_time, load_level) parameters.
+  using Callback = base::RepeatingCallback<void(base::TimeTicks, double)>;
+
+  ThreadLoadTracker(base::TimeTicks now,
+                    const Callback& callback,
+                    base::TimeDelta reporting_interval);
+  ~ThreadLoadTracker();
+
+  void Pause(base::TimeTicks now);
+  void Resume(base::TimeTicks now);
+
+  // Note: this does not change |thread_state_|.
+  void Reset(base::TimeTicks now);
+
+  void RecordTaskTime(base::TimeTicks start_time, base::TimeTicks end_time);
+
+  void RecordIdle(base::TimeTicks now);
+
+  // TODO(altimin): Count wake-ups.
+
+ private:
+  enum class ThreadState { kActive, kPaused };
+
+  enum class TaskState { kTaskRunning, kIdle };
+
+  // This function advances |time_| to |now|, calling |callback_|
+  // in the process (multiple times if needed).
+  void Advance(base::TimeTicks now, TaskState task_state);
+
+  double Load();
+
+  // |time_| is the last timestamp LoadTracker knows about.
+  base::TimeTicks time_;
+  base::TimeTicks next_reporting_time_;
+
+  ThreadState thread_state_;
+  base::TimeTicks last_state_change_time_;
+
+  base::TimeDelta reporting_interval_;
+
+  // Recorded run time in window
+  // [next_reporting_time - reporting_interval, next_reporting_time].
+  base::TimeDelta run_time_inside_window_;
+
+  Callback callback_;
+};
+
+}  // namespace scheduler
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_UTIL_THREAD_LOAD_TRACKER_H_