Remove balloon notification code. The last user was the Linux GTK port but that's deleted now.

chrome/common/pref_names.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 "chrome/common/pref_names.h"
 
 #include "base/basictypes.h"
 #include "chrome/common/pref_font_webkit_names.h"
 
 namespace prefs {
@@ skipping 1011 matching lines @@
 // asking the user to set up automatic updates when Keystone promotion is
 // required.
 const char kShowUpdatePromotionInfoBar[] =
     "browser.show_update_promotion_info_bar";
 #endif
 
 // Boolean that is false if we should show window manager decorations.  If
 // true, we draw a custom chrome frame (thicker title bar and blue border).
 const char kUseCustomChromeFrame[] = "browser.custom_chrome_frame";
 
-// The preferred position (which corner of screen) for desktop notifications.
-const char kDesktopNotificationPosition[] =
-    "browser.desktop_notification_position";
-
 // Dictionary of content settings applied to all hosts by default.
 const char kDefaultContentSettings[] = "profile.default_content_settings";
 
 // Boolean indicating whether the clear on exit pref was migrated to content
 // settings yet.
 const char kContentSettingsClearOnExitMigrated[] =
     "profile.content_settings.clear_on_exit_migrated";
 
 // Version of the pattern format used to define content settings.
 const char kContentSettingsVersion[] = "profile.content_settings.pref_version";
@@ skipping 1525 matching lines @@
 // "mapped_title" entries, detailing the bookmark target URL (if any), the title
 // given by the PartnerBookmarksProvider and either the user-visible renamed
 // title or an empty string if the bookmark node was removed.
 const char kPartnerBookmarkMappings[] = "partnerbookmarks.mappings";
 #endif
 
 // Whether DNS Quick Check is disabled in proxy resolution.
 const char kQuickCheckEnabled[] = "proxy.quick_check_enabled";
 
 }  // namespace prefs