WIP POC blob transport over mojo

content/child/blob_storage/webblobregistry_impl.cc

Index: content/child/blob_storage/webblobregistry_impl.cc
diff --git a/content/child/blob_storage/webblobregistry_impl.cc b/content/child/blob_storage/webblobregistry_impl.cc
index cda1464ea98f236fd0c8baf8bb29050bb77f34d7..2f24dfd1e35b6fcd28e1ea7b7b449be037f55777 100644
--- a/content/child/blob_storage/webblobregistry_impl.cc
+++ b/content/child/blob_storage/webblobregistry_impl.cc
@@ -50,6 +50,10 @@ WebBlobRegistryImpl::WebBlobRegistryImpl(
 WebBlobRegistryImpl::~WebBlobRegistryImpl() {
 }
 
+base::SingleThreadTaskRunner* WebBlobRegistryImpl::GetIORunner() {
+  return io_runner_.get();
+}
+
 std::unique_ptr<WebBlobRegistry::Builder> WebBlobRegistryImpl::CreateBuilder(
     const blink::WebString& uuid,
     const blink::WebString& content_type) {