Make floor-control more robust.

remoting/host/client_session.h

Index: remoting/host/client_session.h
diff --git a/remoting/host/client_session.h b/remoting/host/client_session.h
index dded94a00b944c1c657f409be9a384d2989a486f..b8339fbadd3ccc373e80c8b3bc2492aeeda948ca 100644
--- a/remoting/host/client_session.h
+++ b/remoting/host/client_session.h
@@ -113,7 +113,12 @@ class ClientSession : public protocol::HostStub,
 
   // State to control remote input blocking while the local pointer is in use.
   uint32 remote_mouse_button_state_;
-  std::list<gfx::Point> recent_remote_mouse_positions_;
+
+  // Queue of recently-injected mouse positions.  This is used to detect whether
+  // mouse events from the local input monitor are echoes of injected positions,
+  // or genuine mouse movements of a local input device.
+  std::list<gfx::Point> injected_mouse_positions_;
+
   base::Time latest_local_input_time_;
   std::set<int> pressed_keys_;