Factor File API's 'partial interface URL' impl into separate files

third_party/WebKit/Source/core/fileapi/URLFileAPI.idl

Index: third_party/WebKit/Source/core/fileapi/URLFileAPI.idl
diff --git a/third_party/WebKit/Source/core/fileapi/URLFileAPI.idl b/third_party/WebKit/Source/core/fileapi/URLFileAPI.idl
new file mode 100644
index 0000000000000000000000000000000000000000..262e85f7e32e328ad78bced2b3b29a6b46c569f5
--- /dev/null
+++ b/third_party/WebKit/Source/core/fileapi/URLFileAPI.idl
@@ -0,0 +1,11 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://w3c.github.io/FileAPI/#creating-revoking
+partial interface URL {
+    [CallWith=ExecutionContext, RaisesException] static DOMString createObjectURL(Blob blob);
+    // TODO(jsbell): Implement createFor()
+    //static DOMString createFor(Blob blob);
+    [CallWith=ExecutionContext] static void revokeObjectURL(DOMString url);
+};