Add support for blob urls for subresources.

content/common/renderer_host.mojom

+// Copyright 2017 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.
+
+module content.mojom;
+
+import "content/common/url_loader_factory.mojom";
+
+// The primordial interface implemented by a render process host. This should be
+// used for implementing renderer-to-browser messages.
+interface RendererHost {
+  // Returns a URLLoaderFactory for the blob scheme.

[Ken Rockot(use gerrit already), 2017/06/06 21:49:58]

super nit: maybe s/Returns/Requests/

[jam, 2017/06/06 22:14:39]

Done.

+  GetBlobURLLoaderFactory(URLLoaderFactory& loader);
+};