Mojo C++ bindings: remove the single-threaded Router.

mojo/public/cpp/bindings/strong_binding.h

Index: mojo/public/cpp/bindings/strong_binding.h
diff --git a/mojo/public/cpp/bindings/strong_binding.h b/mojo/public/cpp/bindings/strong_binding.h
index 99d10956c6f040e2835ff9f705f713f38486a641..07f0c164d82d7fb2fd1caa30b02ca167534d8fdb 100644
--- a/mojo/public/cpp/bindings/strong_binding.h
+++ b/mojo/public/cpp/bindings/strong_binding.h
@@ -19,7 +19,6 @@
 #include "mojo/public/cpp/bindings/filter_chain.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
-#include "mojo/public/cpp/bindings/lib/router.h"
 #include "mojo/public/cpp/bindings/message_header_validator.h"
 #include "mojo/public/cpp/system/core.h"
 
@@ -76,9 +75,6 @@ class StrongBinding {
 
   Interface* impl() { return impl_.get(); }
 
-  // Exposed for testing, should not generally be used.
-  internal::Router* internal_router() { return binding_.internal_router(); }
-
   // Sends a message on the underlying message pipe and runs the current
   // message loop until its response is received. This can be used in tests to
   // verify that no message was sent on a message pipe in response to some