Mojo C++ Bindings: Introduce mojo::SupportsStrongBinding

mojo/public/cpp/bindings/tests/handle_passing_unittest.cc

Index: mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc b/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
index feeeef2803568ec0dbb726d35bf9478baa0a6ce4..7c5f64103b712835394f52cc2b8cb400e0a8b4e6 100644
--- a/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
@@ -54,7 +54,8 @@ class ImportedInterfaceImpl : public imported::ImportedInterface {
 };
 int ImportedInterfaceImpl::do_something_count_ = 0;
 
-class SampleNamedObjectImpl : public sample::NamedObject {
+class SampleNamedObjectImpl
+    : public SupportsStrongBinding<sample::NamedObject> {
  public:
   SampleNamedObjectImpl() {}