Add touch events to the protocol, the stub layer, and to the client plugin.

remoting/host/ipc_input_injector.cc

Index: remoting/host/ipc_input_injector.cc
diff --git a/remoting/host/ipc_input_injector.cc b/remoting/host/ipc_input_injector.cc
index fd347e7c6a7941c257bfeba90bc2255752d5ceda..d81ea7272b845f2df3385aca5a9bfe9e2f565a5d 100644
--- a/remoting/host/ipc_input_injector.cc
+++ b/remoting/host/ipc_input_injector.cc
@@ -33,6 +33,10 @@ void IpcInputInjector::InjectMouseEvent(const protocol::MouseEvent& event) {
   desktop_session_proxy_->InjectMouseEvent(event);
 }
 
+void IpcInputInjector::InjectTouchEvent(const protocol::TouchEvent& event) {
+  NOTIMPLEMENTED();
+}
+
 void IpcInputInjector::Start(
     scoped_ptr<protocol::ClipboardStub> client_clipboard) {
   desktop_session_proxy_->StartInputInjector(client_clipboard.Pass());