Unregister test event tick clock to avoid crash

BUG=1060156

TEST=events_unittests --gtest_filter=XEventTranslationTest.*

Change-Id: I8e26af89d45edb24027a2d53c7b25cbe824bf0b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2096640Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Tomasz Moniuszko <tmoniuszko@opera.com>
Cr-Commit-Position: refs/heads/master@{#749076}

ui/events/test/scoped_event_test_tick_clock.h

@@ -6,6 +6,7 @@
 #define UI_EVENTS_TEST_SCOPED_EVENT_TEST_TICK_CLOCK_H_
 
 #include "base/test/simple_test_tick_clock.h"
+#include "base/time/time.h"
 #include "ui/events/base_event_utils.h"
 
 namespace ui {
@@ -32,6 +33,8 @@ class ScopedEventTestTickClock {
 
   void SetNowTicks(base::TimeTicks ticks) { test_clock_.SetNowTicks(ticks); }
 
+  void Advance(base::TimeDelta delta) { test_clock_.Advance(delta); }
+
  private:
   base::SimpleTestTickClock test_clock_;
 

ui/events/x/x11_event_translation_unittest.cc

@@ -4,7 +4,6 @@
 
 #include "ui/events/x/x11_event_translation.h"
 
-#include "base/test/simple_test_tick_clock.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/base_event_utils.h"
@@ -15,6 +14,7 @@
 #include "ui/events/test/events_test_utils.h"
 #include "ui/events/test/events_test_utils_x11.h"
 #include "ui/events/test/keyboard_layout.h"
+#include "ui/events/test/scoped_event_test_tick_clock.h"
 #include "ui/events/types/event_type.h"
 #include "ui/gfx/x/x11.h"
 
@@ -92,8 +92,7 @@ TEST(XEventTranslationTest, BogusTimestampCorrection) {
   scoped_xev.InitKeyEvent(ET_KEY_PRESSED, VKEY_RETURN, EF_NONE);
   XEvent* xev = scoped_xev;
 
-  base::SimpleTestTickClock test_clock;
-  ui::SetEventTickClockForTesting(&test_clock);
+  test::ScopedEventTestTickClock test_clock;
   test_clock.Advance(TimeDelta::FromSeconds(1));
 
   // Set initial time as 1000ms