src: rename namespace as chronochat

Change-Id: Idf390b1b2047c912735014d078ce099cf95026e6
diff --git a/src/tree-layout.cpp b/src/tree-layout.cpp
index d2c4d2c..166019f 100644
--- a/src/tree-layout.cpp
+++ b/src/tree-layout.cpp
@@ -13,7 +13,7 @@
 #include "tree-layout.hpp"
 #include <iostream>
 
-namespace chronos {
+namespace chronochat {
 
 using std::vector;
 using std::map;
@@ -64,4 +64,4 @@
   }
 }
 
-} // namespace chronos
+} // namespace chronochat