Start an empty interface OffScreenCanvas

third_party/WebKit/Source/core/html/canvas/OffScreenCanvas.idl

Index: third_party/WebKit/Source/core/html/canvas/OffScreenCanvas.idl
diff --git a/third_party/WebKit/Source/core/html/canvas/OffScreenCanvas.idl b/third_party/WebKit/Source/core/html/canvas/OffScreenCanvas.idl
new file mode 100644
index 0000000000000000000000000000000000000000..dd3e4559e10180ddf8ccf7937171f8298e194ea1
--- /dev/null
+++ b/third_party/WebKit/Source/core/html/canvas/OffScreenCanvas.idl
@@ -0,0 +1,12 @@
+// Copyright 2015 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.
+
+[
+    Constructor(unsigned long width, unsigned long height),
+    GarbageCollected,
+    RuntimeEnabled=ExperimentalCanvasFeatures,
+] interface OffScreenCanvas {
+    attribute unsigned long width;
+    attribute unsigned long height;
+};