Cleanup: Remove unneeded forward declarations from various chrome/browser subdirectories.

chrome/browser/autocomplete/history_url_provider.h

 // Copyright (c) 2011 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_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_
 #pragma once
 
 #include <string>
+#include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "chrome/browser/autocomplete/history_provider.h"
 #include "chrome/browser/autocomplete/history_provider_util.h"
 
 class MessageLoop;
 class Profile;
 
 namespace history {
 
 class HistoryBackend;
 class URLDatabase;
-class URLRow;
 
 }  // namespace history
 
 // How history autocomplete works
 // ==============================
 //
 // Read down this diagram for temporal ordering.
 //
 //   Main thread                History thread
 //   -----------                --------------
@@ skipping 245 matching lines @@
   // parameter itself is freed once it's no longer needed.  The only reason we
   // keep this member is so we can set the cancel bit on it.
   HistoryURLProviderParams* params_;
 
   // Only used by unittests; if non-empty, overrides accept-languages in the
   // profile's pref system.
   std::string languages_;
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_HISTORY_URL_PROVIDER_H_