Remove custom getters for File.lastModified{Date}

Source/core/fileapi/File.idl

Index: Source/core/fileapi/File.idl
diff --git a/Source/core/fileapi/File.idl b/Source/core/fileapi/File.idl
index a3c21cb0524e75dce86f4f079e7ef4a9226786df..c338fa2948e5d1b8cf2edd1a60af626a647a46bc 100644
--- a/Source/core/fileapi/File.idl
+++ b/Source/core/fileapi/File.idl
@@ -28,7 +28,7 @@
     Exposed=(Window,Worker),
 ] interface File : Blob {
     readonly attribute DOMString name;
-    [Custom=Getter, MeasureAs=FileGetLastModifiedDate] readonly attribute Date lastModifiedDate;
-    [Custom=Getter, RuntimeEnabled=FileConstructor] readonly attribute long long lastModified;
+    [MeasureAs=FileGetLastModifiedDate] readonly attribute Date lastModifiedDate;
+    readonly attribute long long lastModified;
     [MeasureAs=PrefixedFileRelativePath] readonly attribute DOMString webkitRelativePath;
 };