Mojo JS Bindings: Mojo handles need a toString() method

mojo/bindings/js/handle.h

Index: mojo/bindings/js/handle.h
diff --git a/mojo/bindings/js/handle.h b/mojo/bindings/js/handle.h
index b0f250c61a5f2c99477260cbc50fa493876e929e..f045ee3a52ea4fd77fdaf3d93d39c92fd288895d 100644
--- a/mojo/bindings/js/handle.h
+++ b/mojo/bindings/js/handle.h
@@ -8,6 +8,7 @@
 #include "base/observer_list.h"
 #include "gin/converter.h"
 #include "gin/handle.h"
+#include "gin/object_template_builder.h"
 #include "gin/wrappable.h"
 #include "mojo/public/cpp/system/core.h"
 
@@ -26,6 +27,11 @@ class HandleWrapper : public gin::Wrappable<HandleWrapper> {
     return gin::CreateHandle(isolate, new HandleWrapper(handle));
   }
 
+  std::string ToString();
+
+  gin::ObjectTemplateBuilder GetObjectTemplateBuilder(v8::Isolate* isolate)
+      override;
+
   mojo::Handle get() const { return handle_.get(); }
   mojo::Handle release() { return handle_.release(); }
   void Close();