Import FileAPI tests from web-platform-tests

LayoutTests/imported/web-platform-tests/FileAPI/idlharness.idl

+[Constructor,
+ Constructor(sequence<(ArrayBuffer or ArrayBufferView or Blob or DOMString)> blobParts, optional BlobPropertyBag options), Exposed=Window,Worker]
+interface Blob {
+
+  readonly attribute unsigned long long size;
+  readonly attribute DOMString type;
+  readonly attribute boolean isClosed;
+
+  //slice Blob into byte-ranged chunks
+
+  Blob slice([Clamp] optional long long start,
+             [Clamp] optional long long end,
+             optional DOMString contentType);
+  void close();
+
+};
+
+dictionary BlobPropertyBag {
+  DOMString type = "";
+};
+
+[Constructor(sequence<(Blob or DOMString or ArrayBufferView or ArrayBuffer)> fileBits,
+[EnsureUTF16] DOMString fileName, optional FilePropertyBag options), Exposed=Window,Worker]
+interface File : Blob {
+
+  readonly attribute DOMString name;
+  readonly attribute long long lastModified;
+
+};
+
+dictionary FilePropertyBag {
+
+  DOMString type = "";
+  long long lastModified;
+
+};
+
+[Exposed=Window,Worker] interface FileList {
+  getter File? item(unsigned long index);
+  readonly attribute unsigned long length;
+};
+
+[Constructor, Exposed=Window,Worker]
+interface FileReader: EventTarget {
+
+  // async read methods
+  void readAsArrayBuffer(Blob blob);
+  void readAsText(Blob blob, optional DOMString label);
+  void readAsDataURL(Blob blob);
+
+  void abort();
+
+  // states
+  const unsigned short EMPTY = 0;
+  const unsigned short LOADING = 1;
+  const unsigned short DONE = 2;
+
+  readonly attribute unsigned short readyState;
+
+  // File or Blob data
+  readonly attribute (DOMString or ArrayBuffer)? result;
+
+  readonly attribute DOMError? error;
+
+  // event handler attributes
+  attribute EventHandler onloadstart;
+  attribute EventHandler onprogress;
+  attribute EventHandler onload;
+  attribute EventHandler onabort;
+  attribute EventHandler onerror;
+  attribute EventHandler onloadend;
+
+};
+
+partial interface URL {
+
+  static DOMString createObjectURL(Blob blob);
+  static DOMString createFor(Blob blob);
+  static void revokeObjectURL(DOMString url);
+
+};