Improve grammar in some comments.

ash/common/system/tray/system_tray.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/tray/system_tray.h"
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/login_status.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 154 matching lines @@
   WmShell* wm_shell = WmShell::Get();
 #if !defined(OS_WIN)
   // Create user items for each possible user.
   int maximum_user_profiles =
       wm_shell->GetSessionStateDelegate()->GetMaximumNumberOfLoggedInUsers();
   for (int i = 0; i < maximum_user_profiles; i++)
     AddTrayItem(new TrayUser(this, i));
 
   if (maximum_user_profiles > 1) {
     // Add a special double line separator between users and the rest of the
-    // menu if more then one user is logged in.
+    // menu if more than one user is logged in.
     AddTrayItem(new TrayUserSeparator(this));
   }
 #endif
 
   tray_accessibility_ = new TrayAccessibility(this);
   tray_date_ = new TrayDate(this);
   tray_update_ = new TrayUpdate(this);
 
 #if defined(OS_CHROMEOS)
   AddTrayItem(new TraySessionLengthLimit(this));
@@ skipping 581 matching lines @@
           .work_area()
           .height();
   if (work_area_height > 0) {
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Ash.SystemMenu.PercentageOfWorkAreaHeightCoveredByMenu",
         100 * bubble_view->height() / work_area_height, 1, 300, 100);
   }
 }
 
 }  // namespace ash