Fix the typo "visibility".

chrome/browser/ui/views/bookmarks/bookmark_bar_view_unittest.cc

 // Copyright 2013 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 "chrome/browser/ui/views/bookmarks/bookmark_bar_view.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
@@ skipping 140 matching lines @@
   } else {
     EXPECT_TRUE(test_helper_->apps_page_shortcut()->visible());
   }
 
   // Make sure we can also properly transition from true to false.
   browser()->profile()->GetPrefs()->SetBoolean(
       bookmarks::prefs::kShowAppsShortcutInBookmarkBar, false);
   EXPECT_FALSE(test_helper_->apps_page_shortcut()->visible());
 }
 
-// Various assertions around visibilty of the overflow_button.
+// Various assertions around visibility of the overflow_button.
 TEST_F(BookmarkBarViewTest, OverflowVisibility) {
   profile()->CreateBookmarkModel(true);
   CreateBookmarkBarView();
   EXPECT_FALSE(test_helper_->overflow_button()->visible());
 
   WaitForBookmarkModelToLoad();
   AddNodesToBookmarkBarFromModelString("a b c d e f ");
   EXPECT_TRUE(test_helper_->overflow_button()->visible());
 
   SizeUntilButtonsVisible(1);
@@ skipping 171 matching lines @@
   prefs->SetManagedPref(bookmarks::prefs::kShowAppsShortcutInBookmarkBar,
                         new base::FundamentalValue(false));
   EXPECT_FALSE(test_helper_->apps_page_shortcut()->visible());
 
   // And try showing it via policy too.
   prefs->SetManagedPref(bookmarks::prefs::kShowAppsShortcutInBookmarkBar,
                         new base::FundamentalValue(true));
   EXPECT_TRUE(test_helper_->apps_page_shortcut()->visible());
 }
 #endif