chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/extension_ui_util.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_UI_UTIL_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_UI_UTIL_H_
 
 namespace content {
 class BrowserContext;
-class WebContents;
 }
 
 namespace extensions {
 
 class Extension;
 
 namespace ui_util {
 
 // Returns true if the extension should be displayed in the app launcher.
 // Checks whether the extension is an ephemeral app or should be hidden due to
@@ skipping 23 matching lines @@
 // mostly the same as the extension being a component extension, but also
 // includes non-component apps that are hidden from the app launcher and NTP,
 // as well as ephemeral apps.
 bool ShouldNotBeVisible(const Extension* extension,
                         content::BrowserContext* context);
 
 }  // namespace ui_util
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_UI_UTIL_H_