Remove TODOs for switching elapsedTime from double to float

https://github.com/w3c/csswg-drafts/pull/2666 and
https://github.com/w3c/csswg-drafts/pull/2671 updated the spec so that
elapsedTime as a member of AnimationEvent and TransitionEvent is
specified as a double instead of a float. Remove the TODOs as our
implementation is now correct.

Change-Id: I1c7abf14765fdbd46e37b4f8c506fed574cecdd0
Reviewed-on: https://chromium-review.googlesource.com/1056787Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Commit-Queue: Chris Nardi <cnardi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558285}

third_party/blink/renderer/core/events/animation_event.idl

@@ -29,7 +29,6 @@
     Constructor(DOMString type, optional AnimationEventInit eventInitDict)
 ] interface AnimationEvent : Event {
     readonly attribute DOMString animationName;
-    // TODO(foolip): elapsedTime should be float.
     readonly attribute double elapsedTime;
     readonly attribute DOMString pseudoElement;
 };

third_party/blink/renderer/core/events/animation_event_init.idl

@@ -6,7 +6,6 @@
 
 dictionary AnimationEventInit : EventInit {
     DOMString animationName = "";
-    // TODO(foolip): elapsedTime should be float.
     double elapsedTime = 0.0;
     DOMString pseudoElement = "";
 };

third_party/blink/renderer/core/events/transition_event.idl

@@ -30,7 +30,6 @@
     Constructor(DOMString type, optional TransitionEventInit eventInitDict)
 ] interface TransitionEvent : Event {
     readonly attribute DOMString propertyName;
-    // TODO(foolip): elapsedTime should be float.
     readonly attribute double elapsedTime;
     readonly attribute DOMString pseudoElement;
 };