Add the plumbing that will carry a clipboard item from a chromoting client to a host.

remoting/protocol/client_event_dispatcher.cc

Index: remoting/protocol/client_event_dispatcher.cc
diff --git a/remoting/protocol/client_event_dispatcher.cc b/remoting/protocol/client_event_dispatcher.cc
index c0da8373f2cdcf2e8cf08aa8149e35b3edcbd1cf..0647db1b190baa405889ed4004fcc653cae27ab6 100644
--- a/remoting/protocol/client_event_dispatcher.cc
+++ b/remoting/protocol/client_event_dispatcher.cc
@@ -31,6 +31,13 @@ void ClientEventDispatcher::OnInitialized() {
                 BufferedSocketWriter::WriteFailedCallback());
 }
 
+void ClientEventDispatcher::InjectClipboardEvent(const ClipboardEvent& event) {
+  EventMessage message;
+  message.set_sequence_number(base::Time::Now().ToInternalValue());
+  message.mutable_clipboard_event()->CopyFrom(event);
+  writer_->Write(SerializeAndFrameMessage(message), base::Closure());
+}
+
 void ClientEventDispatcher::InjectKeyEvent(const KeyEvent& event) {
   EventMessage message;
   message.set_sequence_number(base::Time::Now().ToInternalValue());