[PresentationAPI] Implementing send() from WebPresentationClient to the PresentationService.

content/browser/presentation/presentation_service_impl.cc

Index: content/browser/presentation/presentation_service_impl.cc
diff --git a/content/browser/presentation/presentation_service_impl.cc b/content/browser/presentation/presentation_service_impl.cc
index 9e2fd22e9c8c59971ce8f898b92864e220704a2e..0915dbfdbb1b8b017e73742d626d0ff3442b01c6 100644
--- a/content/browser/presentation/presentation_service_impl.cc
+++ b/content/browser/presentation/presentation_service_impl.cc
@@ -300,6 +300,24 @@ void PresentationServiceImpl::SetDefaultPresentationURL(
   DoSetDefaultPresentationUrl(new_default_url, default_presentation_id);
 }
 
+void PresentationServiceImpl::SendMessage(
+    presentation::MessageRequestPtr message_request,
+    const SendMessageMojoCallback& callback) {
+  DCHECK(!message_request.is_null());
+  if (delegate_) {
+    // TODO(s.singapati): delegate_->SendMessage() is currently disabled
+    //because of invalid include path of presentation_message.h.
+    /*
+    delegate_->SendMessage(
+        render_frame_host_->GetProcess()->GetID(),
+        render_frame_host_->GetRoutingID(),
+        new MessageRequest(message_request.Pass()));
+        */
+  }
+
+  callback.Run();
+}
+
 void PresentationServiceImpl::CloseSession(
     const mojo::String& presentation_url,
     const mojo::String& presentation_id) {