Implement convertToBlob() in OffscreenCanvas

third_party/WebKit/Source/core/offscreencanvas/ImageEncodeOptions.idl

Index: third_party/WebKit/Source/core/offscreencanvas/ImageEncodeOptions.idl
diff --git a/third_party/WebKit/Source/core/offscreencanvas/ImageEncodeOptions.idl b/third_party/WebKit/Source/core/offscreencanvas/ImageEncodeOptions.idl
new file mode 100644
index 0000000000000000000000000000000000000000..8836b49a4f64df46b8cb67aa07ef7bb92b8c3e66
--- /dev/null
+++ b/third_party/WebKit/Source/core/offscreencanvas/ImageEncodeOptions.idl
@@ -0,0 +1,10 @@
+// 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://wiki.whatwg.org/wiki/OffscreenCanvas
+
+dictionary ImageEncodeOptions {
+  DOMString type = "image/png";
+  unrestricted double quality = 1.0; // Defaults to 1.0 if value is outside 0:1 range
+};