Remove unnecessary mocking of TickClock for events

ui/chromeos/touch_exploration_controller.h

 // Copyright 2014 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_EXPLORATION_CONTROLLER_H_
 #define UI_CHROMEOS_TOUCH_EXPLORATION_CONTROLLER_H_
 
 #include "base/macros.h"
-#include "base/time/tick_clock.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/chromeos/ui_chromeos_export.h"
 #include "ui/events/event.h"
 #include "ui/events/event_rewriter.h"
 #include "ui/events/gesture_detection/gesture_detector.h"
 #include "ui/events/gestures/gesture_provider_aura.h"
 #include "ui/gfx/geometry/point.h"
 
@@ skipping 474 matching lines @@
 
   // The previous state entered.
   State prev_state_;
 
   // A copy of the previous event passed.
   std::unique_ptr<ui::TouchEvent> prev_event_;
 
   // This toggles whether VLOGS are turned on or not.
   bool VLOG_on_;
 
-  // When touch_exploration_controller 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(TouchExplorationController);
 };
 
 }  // namespace ui
 
 #endif  // UI_CHROMEOS_TOUCH_EXPLORATION_CONTROLLER_H_