Change ui::Event::time_stamp from TimeDelta to TimeTicks

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"
@@ skipping 225 matching lines @@
       const ui::TouchEvent& event,
       std::unique_ptr<ui::Event>* rewritten_event);
   ui::EventRewriteStatus InSlideGesture(
       const ui::TouchEvent& event,
       std::unique_ptr<ui::Event>* rewritten_event);
   ui::EventRewriteStatus InTwoFingerTap(
       const ui::TouchEvent& event,
       std::unique_ptr<ui::Event>* rewritten_event);
 
   // Returns the current time of the tick clock.
-  base::TimeDelta Now();
+  base::TimeTicks Now();
 
   // This timer is started every time we get the first press event, and
   // it fires after the double-click timeout elapses (300 ms by default).
   // If the user taps and releases within 300 ms and doesn't press again,
   // we treat that as a single mouse move (touch exploration) event.
   void StartTapTimer();
   void OnTapTimerFired();
 
   // This timer is started every timer we get the first press event and the
   // finger is in the corner of the screen.
@@ skipping 247 matching lines @@
   // 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_