Web Animations: Expose timeline currentTime in IDL

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 151 matching lines @@
     EXPECT_TRUE(anim->activeInterpolations().isEmpty());
 
     platformTiming->expectNoMoreActions();
     updateClockAndService(100);
     EXPECT_FLOAT_EQ(100, timeline->currentTime());
 }
 
 TEST_F(AnimationDocumentTimelineTest, ZeroTime)
 {
     timeline = DocumentTimeline::create(document.get());
+    bool isNull;
 
     document->animationClock().updateTime(100);
-    EXPECT_TRUE(isNull(timeline->currentTime()));
+    EXPECT_TRUE(std::isnan(timeline->currentTime()));
+    EXPECT_TRUE(std::isnan(timeline->currentTime(isNull)));
+    EXPECT_TRUE(isNull);
 
     document->animationClock().updateTime(200);
-    EXPECT_TRUE(isNull(timeline->currentTime()));
+    EXPECT_TRUE(std::isnan(timeline->currentTime()));
 
     timeline->setZeroTime(300);
     document->animationClock().updateTime(300);
     EXPECT_EQ(0, timeline->currentTime());
+    EXPECT_EQ(0, timeline->currentTime(isNull));
+    EXPECT_FALSE(isNull);
 
     document->animationClock().updateTime(400);
     EXPECT_EQ(100, timeline->currentTime());
 }
 
 TEST_F(AnimationDocumentTimelineTest, PauseForTesting)
 {
     float seekTime = 1;
     timing.fillMode = Timing::FillModeForwards;
     RefPtr<Animation> anim1 = Animation::create(element.get(), KeyframeEffectModel::create(KeyframeEffectModel::KeyframeVector()), timing);
@@ skipping 94 matching lines @@
 
 TEST_F(AnimationDocumentTimelineTest, UseAnimationPlayerAfterTimelineDeref)
 {
     RefPtr<AnimationPlayer> player = timeline->createAnimationPlayer(0);
     timeline.clear();
     // Test passes if this does not crash.
     player->setStartTime(0);
 }
 
 }