chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/install_verifier.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_
 #define CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_
 
 #include <memory>
 #include <queue>
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "extensions/browser/management_policy.h"
 #include "extensions/common/extension.h"
 
 namespace content {
 class BrowserContext;
 }
 
-namespace net {
-class URLRequestContextGetter;
-}
-
 namespace extensions {
 
 class ExtensionPrefs;
 class InstallSigner;
 struct InstallSignature;
 
 // This class implements verification that a set of extensions are either from
 // the webstore or are whitelisted by enterprise policy.  The webstore
 // verification process works by sending a request to a backend server to get a
 // signature proving that a set of extensions are verified. This signature is
@@ skipping 153 matching lines @@
   static bool ShouldBypass();
 
  private:
   bool old_value_;
   DISALLOW_COPY_AND_ASSIGN(ScopedInstallVerifierBypassForTest);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_