Implement requestIdleCallback API

LayoutTests/webexposed/global-interface-listing-expected.txt

Index: LayoutTests/webexposed/global-interface-listing-expected.txt
diff --git a/LayoutTests/webexposed/global-interface-listing-expected.txt b/LayoutTests/webexposed/global-interface-listing-expected.txt
index 752d9e4bbb9fc5ee8e0bf68fcb1748d04673ca6b..611a6220ecd78e8b0cc75b8d74ba3a7d862e1eb5 100644
--- a/LayoutTests/webexposed/global-interface-listing-expected.txt
+++ b/LayoutTests/webexposed/global-interface-listing-expected.txt
@@ -3050,6 +3050,11 @@ interface IDBVersionChangeEvent
     getter newVersion
     getter oldVersion
     method constructor
+interface IdleCallbackDeadline
+    getter deadline
+    getter didTimeout
+    method constructor
+    method isExceeded
 interface Image
     method constructor
 interface ImageBitmap
@@ -6274,6 +6279,7 @@ interface Window
     method blur
     method btoa
     method cancelAnimationFrame
+    method cancelIdleCallback
     method captureEvents
     method clearInterval
     method clearTimeout
@@ -6298,6 +6304,7 @@ interface Window
     method prompt
     method releaseEvents
     method requestAnimationFrame
+    method requestIdleCallback
     method resizeBy
     method resizeTo
     method scroll