Revert of Remove supports_touch_events flag from BasicDesktopEnvironment

remoting/host/desktop_session_proxy.h

Index: remoting/host/desktop_session_proxy.h
diff --git a/remoting/host/desktop_session_proxy.h b/remoting/host/desktop_session_proxy.h
index 53ffcad09037ecb394e91329f81994456c5b6c3c..01222a825dca5e99ce67d3e41bdf297958feedbb 100644
--- a/remoting/host/desktop_session_proxy.h
+++ b/remoting/host/desktop_session_proxy.h
@@ -76,7 +76,8 @@
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       base::WeakPtr<ClientSessionControl> client_session_control,
       base::WeakPtr<DesktopSessionConnector> desktop_session_connector,
-      bool virtual_terminal);
+      bool virtual_terminal,
+      bool supports_touch_events);
 
   // Mirrors DesktopEnvironment.
   std::unique_ptr<AudioCapturer> CreateAudioCapturer();
@@ -222,6 +223,9 @@
 
   bool virtual_terminal_;
 
+  // True if touch events are supported by the desktop session.
+  bool supports_touch_events_;
+
   // Stores the session id for the proxied desktop process.
   uint32_t desktop_session_id_ = UINT32_MAX;