[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..0460f3fec59a2a549fc3ba2d86ecb8356dcb4a6f 100644
--- a/content/browser/presentation/presentation_service_impl.cc
+++ b/content/browser/presentation/presentation_service_impl.cc
@@ -300,6 +300,20 @@ void PresentationServiceImpl::SetDefaultPresentationURL(
   DoSetDefaultPresentationUrl(new_default_url, default_presentation_id);
 }
 
+void PresentationServiceImpl::SendStringMessage(
+    const mojo::String& presentation_url,
+    const mojo::String& presentation_id,
+    const mojo::String& message,
+    const SendMessageMojoCallback& callback) {
+  if (!delegate_) {
+    callback.Run();
+    return;
+  }
+  // TODO(s.singapati): Save the callback into send_message_cb_ptr_
+  // and run it after request completion by delegate_.
+  NOTIMPLEMENTED();
+}
+
 void PresentationServiceImpl::CloseSession(
     const mojo::String& presentation_url,
     const mojo::String& presentation_id) {
@@ -373,6 +387,11 @@ void PresentationServiceImpl::Reset() {
     InvokeNewSessionMojoCallbackWithError(*pending_entry.second);
   }
   pending_session_cbs_.clear();
+
+  if (send_message_cb_ptr_) {
+    send_message_cb_ptr_->Run();

[whywhat, 2015/04/13 13:31:21]

This might result in the PresentationDispatcher sending the next message. Either
we need to run the callback with an error or just reset it (if that doesn't
break Mojo connection).

[USE s.singapati at gmail.com, 2015/04/14 17:51:51]

Done. callback is Reset for now. May be Mojo disconnection from the frame is not
a issue since the frame is closing anyway? (Or it needs a callback like
OnSendMessageCallback(bool success) in PresentationDispatcher.)

+    send_message_cb_ptr_.reset();
+  }
 }
 
 void PresentationServiceImpl::InvokeNewSessionMojoCallbackWithError(