Update two chromeos system dialogs to reuse more DialogDelegateView

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 91c573ed0640a1f095e9cd4ec105a2db9d781c4b..9f2ca2fc04fecfc2b2dfc1d966beeb9a959f1b44 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -1032,9 +1032,8 @@ are declared in build/common.gypi.
         </message>
         <message name="IDS_VISIT_DESKTOP_WARNING_MESSAGE" desc="The message on the dialog which warns user about oddities which can be seen when a window gets moved to another user desktop.">
           Moving windows to another desktop may result in unexpected behaviour.
-        </message>
-        <message name="IDS_VISIT_DESKTOP_WARNING_EXPLANATION" desc="The explanation message on the dialog which warns user about oddities which can be seen when a window gets moved to another user desktop.">
-          Subsequent notifications, windows and dialogs may be split between desktops.
+
+Subsequent notifications, windows and dialogs may be split between desktops.
         </message>
         <message name="IDS_VISIT_DESKTOP_WARNING_SHOW_DISMISS" desc="Label for checkbox dismissing show of teleportation warning dialog.">
           Got it, don't show me again.