Revert of Optimize for TouchStart responsiveness

components/scheduler/renderer/user_model.h

-// Copyright 2015 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 COMPONENTS_SCHEDULER_RENDERER_USER_MODEL_H_
-#define COMPONENTS_SCHEDULER_RENDERER_USER_MODEL_H_
-
-#include "base/macros.h"
-#include "base/trace_event/trace_event.h"
-#include "base/trace_event/trace_event_argument.h"
-#include "components/scheduler/renderer/renderer_scheduler.h"
-#include "components/scheduler/scheduler_export.h"
-#include "third_party/WebKit/public/web/WebInputEvent.h"
-
-namespace scheduler {
-
-class SCHEDULER_EXPORT UserModel {
- public:
-  UserModel();
-  ~UserModel();
-
-  // Tells us that the system started processing an input event. Must be paired
-  // with a call to DidFinishProcessingInputEvent.
-  void DidStartProcessingInputEvent(blink::WebInputEvent::Type type,
-                                    const base::TimeTicks now);
-
-  // Tells us that the system finished processing an input event.
-  void DidFinishProcessingInputEvent(const base::TimeTicks now);
-
-  // Returns the estimated amount of time left in the current user gesture, to a
-  // maximum of |kGestureEstimationLimitMillis|.  After that time has elapased
-  // this function should be called again.
-  base::TimeDelta TimeLeftInUserGesture(base::TimeTicks now) const;
-
-  // Tries to guess if a user gesture is expected soon. Currently this is
-  // very simple, but one day I hope to do something more sophisticated here.
-  // The prediction may change after |prediction_valid_duration| has elapsed.
-  bool IsGestureExpectedSoon(RendererScheduler::UseCase use_case,
-                             const base::TimeTicks now,
-                             base::TimeDelta* prediction_valid_duration) const;
-
-  void AsValueInto(base::trace_event::TracedValue* state) const;
-
-  // The time we should stay in a priority-escalated mode after an input event.
-  static const int kGestureEstimationLimitMillis = 100;
-
-  // TODO(alexclarke): Get a real number on actual data.
-  static const int kMinimumTypicalScrollDurationMillis = 500;
-
-  // We consider further gesture start events to be likely if the user has
-  // interacted with the device in the past two seconds.
-  // TODO(alexclarke): Get a real number based on actual data.
-  static const int kExpectSubsequentGestureMillis = 2000;
-
-  // Clears input signals.
-  void Reset();
-
- private:
-  int pending_input_event_count_;
-  base::TimeTicks last_input_signal_time_;
-  base::TimeTicks last_gesture_start_time_;
-  base::TimeTicks last_continuous_gesture_time_;  // Doesn't include Taps.
-
-  DISALLOW_COPY_AND_ASSIGN(UserModel);
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_RENDERER_USER_MODEL_H_