Implement requestIdleCallback API

Source/core/core.gypi

Index: Source/core/core.gypi
diff --git a/Source/core/core.gypi b/Source/core/core.gypi
index 31c446aad1f251c185915b4642ee2e07f1b8bff5..b68feb2d8938da732fc7337cb79a16f95437978c 100644
--- a/Source/core/core.gypi
+++ b/Source/core/core.gypi
@@ -69,6 +69,8 @@
             'dom/Float32Array.idl',
             'dom/Float64Array.idl',
             'dom/FrameRequestCallback.idl',
+            'dom/IdleCallbackDeadline.idl',
+            'dom/IdleRequestCallback.idl',
             'dom/Int16Array.idl',
             'dom/Int32Array.idl',
             'dom/Int8Array.idl',
@@ -2310,6 +2312,9 @@
             'dom/GlobalEventHandlers.h',
             'dom/IconURL.cpp',
             'dom/IconURL.h',
+            'dom/IdleCallbackDeadline.cpp',
+            'dom/IdleCallbackDeadline.h',
+            'dom/IdleRequestCallback.h',
             'dom/IdTargetObserver.cpp',
             'dom/IdTargetObserver.h',
             'dom/IdTargetObserverRegistry.cpp',
@@ -2390,6 +2395,8 @@
             'dom/ScriptableDocumentParser.h',
             'dom/ScriptedAnimationController.cpp',
             'dom/ScriptedAnimationController.h',
+            'dom/ScriptedIdleTaskController.cpp',
+            'dom/ScriptedIdleTaskController.h',
             'dom/SecurityContext.cpp',
             'dom/SecurityContext.h',
             'dom/SelectorQuery.cpp',