ash: Adjust ascii art comment to avoid looking like multiline comment

ash/wm/window_modality_controller_unittest.cc

Index: ash/wm/window_modality_controller_unittest.cc
diff --git a/ash/wm/window_modality_controller_unittest.cc b/ash/wm/window_modality_controller_unittest.cc
index 22b66f1d98d4c74ddedc24fb57e1d56f57fc9004..e07be1b6a14601d9924011f3041c470cd16dd7a3 100644
--- a/ash/wm/window_modality_controller_unittest.cc
+++ b/ash/wm/window_modality_controller_unittest.cc
@@ -321,9 +321,9 @@ TEST_F(WindowModalityControllerTest, ChangeCapture) {
 // modal window's modal parent window.
 TEST_F(WindowModalityControllerTest, ReleaseCapture) {
   // Create a window hierachy like this:
-  //                            w0
-  //            /               |              \
-  //           w1     <------   w3              w2
+  //            _______________w0______________
+  //            |               |              |
+  //           w1     <------   w3             w2
   //            |    (modal to)
   //           w11