Revert "Toggle spoken feedback if two fingers are held down."

ui/chromeos/touch_accessibility_enabler.h

-// 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 UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_
-#define UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_
-
-#include "base/macros.h"
-#include "base/time/tick_clock.h"
-#include "base/timer/timer.h"
-#include "base/values.h"
-#include "ui/chromeos/ui_chromeos_export.h"
-#include "ui/events/event.h"
-#include "ui/events/event_handler.h"
-#include "ui/events/gesture_detection/gesture_detector.h"
-
-namespace aura {
-class Window;
-}
-
-namespace ui {
-
-class Event;
-class EventHandler;
-class TouchEvent;
-
-// A delegate to handle commands in response to detected accessibility gesture
-// events.
-class TouchAccessibilityEnablerDelegate {
- public:
-  virtual ~TouchAccessibilityEnablerDelegate() {}
-
-  // While the user holds down two fingers on a touch screen, which is the
-  // gesture to enable spoken feedback (if held down long enough), play a sound
-  // every "tick" (approximately every half-second) to warn the user something
-  // is about to happen.
-  virtual void PlaySpokenFeedbackToggleCountdown(int tick_count) {}
-
-  // Toggles spoken feedback.
-  virtual void ToggleSpokenFeedback() {}
-};
-
-// TouchAccessibilityEnabler triggers turning spoken feedback on or off
-// by holding down two fingers on the touch screen for several seconds.
-class UI_CHROMEOS_EXPORT TouchAccessibilityEnabler : public ui::EventHandler {
- public:
-  TouchAccessibilityEnabler(aura::Window* root_window,
-                            ui::TouchAccessibilityEnablerDelegate* delegate);
-  ~TouchAccessibilityEnabler() override;
-
-  bool IsInNoFingersDownForTesting() { return state_ == NO_FINGERS_DOWN; }
-  bool IsInOneFingerDownForTesting() { return state_ == ONE_FINGER_DOWN; }
-  bool IsInTwoFingersDownForTesting() { return state_ == TWO_FINGERS_DOWN; }
-  bool IsInWaitForNoFingersForTesting() {
-    return state_ == WAIT_FOR_NO_FINGERS;
-  }
-  void TriggerOnTimerForTesting() { OnTimer(); }
-
-  void HandleTouchEvent(const ui::TouchEvent& event);
-
- private:
-  // Overridden from ui::EventHandler
-  void OnTouchEvent(ui::TouchEvent* event) override;
-
-  void StartTimer();
-  void CancelTimer();
-  void OnTimer();
-
-  // Returns the current time of the tick clock.
-  base::TimeTicks Now();
-
-  enum State {
-    // No fingers are down.
-    NO_FINGERS_DOWN,
-
-    // One finger is down and it's possible this could be a two-finger-hold.
-    ONE_FINGER_DOWN,
-
-    // Two fingers are down and stationary and we will trigger enabling
-    // spoken feedback after a delay.
-    TWO_FINGERS_DOWN,
-
-    // This is the "reject" state when we get anything other than two fingers
-    // held down and stationary. Stay in this state until all fingers are
-    // removed.
-    WAIT_FOR_NO_FINGERS
-  };
-
-  aura::Window* root_window_;
-
-  // Called when we detect a long-press of two fingers. Not owned.
-  ui::TouchAccessibilityEnablerDelegate* delegate_;
-
-  // The current state.
-  State state_;
-
-  // The time when we entered the two finger state.
-  base::TimeTicks two_finger_start_time_;
-
-  // Map of touch ids to their initial locations.
-  std::map<int, gfx::PointF> touch_locations_;
-
-  // A timer that triggers repeatedly while two fingers are held down.
-  base::RepeatingTimer timer_;
-
-  // A default gesture detector config, so we can share the same
-  // timeout and pixel slop constants.
-  ui::GestureDetector::Config gesture_detector_config_;
-
-  // When touch_accessibility_enabler gets time relative to real time during
-  // testing, this clock is set to the simulated clock and used.
-  base::TickClock* tick_clock_;
-
-  DISALLOW_COPY_AND_ASSIGN(TouchAccessibilityEnabler);
-};
-
-}  // namespace ui
-
-#endif  // UI_CHROMEOS_TOUCH_ACCESSIBILITY_ENABLER_H_