Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/animation/DocumentTimelineTest.cpp

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 234 matching lines @@
     platformTiming->expectNoMoreActions();
     updateClockAndService(3);
     EXPECT_EQ(1U, timeline->numberOfActiveAnimationsForTesting());
 }
 
 TEST_F(AnimationDocumentTimelineTest, DelayBeforeAnimationStart)
 {
     timing.iterationDuration = 2;
     timing.startDelay = 5;
 
-    RefPtr<Animation> anim = Animation::create(element.get(), 0, timing);
+    RefPtr<Animation> anim = Animation::create(element.get(), nullptr, timing);
 
     timeline->play(anim.get());
 
     // TODO: Put the player startTime in the future when we add the capability to change player startTime
     platformTiming->expectDelayedAction(timing.startDelay - minimumDelay());
     updateClockAndService(0);
 
     platformTiming->expectDelayedAction(timing.startDelay - minimumDelay() - 1.5);
     updateClockAndService(1.5);
 
     EXPECT_CALL(*platformTiming, serviceOnNextFrame());
     wake();
 
     platformTiming->expectNextFrameAction();
     updateClockAndService(4.98);
 }
 
 TEST_F(AnimationDocumentTimelineTest, PlayAfterDocumentDeref)
 {
     timing.iterationDuration = 2;
     timing.startDelay = 5;
 
     timeline = document->timeline();
-    element = 0;
-    document = 0;
+    element = nullptr;
+    document = nullptr;
 
-    RefPtr<Animation> anim = Animation::create(0, 0, timing);
+    RefPtr<Animation> anim = Animation::create(nullptr, nullptr, timing);
     // Test passes if this does not crash.
     timeline->play(anim.get());
 }
 
 TEST_F(AnimationDocumentTimelineTest, UsePlayerAfterTimelineDeref)
 {
     RefPtr<Player> player = timeline->createPlayer(0);
     timeline.clear();
     // Test passes if this does not crash.
     player->setStartTime(0);
 }
 
 }