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

chrome/browser/safe_browsing/malware_details_history.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_SAFE_BROWSING_MALWARE_DETAILS_HISTORY_H_
 #define CHROME_BROWSER_SAFE_BROWSING_MALWARE_DETAILS_HISTORY_H_
 #pragma once
 
 // This class gets redirect chain for urls from the history service.
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/hash_tables.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/history/history.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "net/base/completion_callback.h"
 
-class TabContents;
-
 namespace safe_browsing {
 typedef std::vector<GURL> RedirectChain;
 }
 
 class MalwareDetailsRedirectsCollector
     : public base::RefCountedThreadSafe<
           MalwareDetailsRedirectsCollector,
           content::BrowserThread::DeleteOnUIThread>,
       public content::NotificationObserver {
-
  public:
   explicit MalwareDetailsRedirectsCollector(Profile* profile);
   virtual ~MalwareDetailsRedirectsCollector();
 
   // Collects urls' redirects chain information from the history service.
   // We get access to history service via tab_contents in UI thread.
   // Notice the callback will be posted to the IO thread.
   void StartHistoryCollection(const std::vector<GURL>& urls,
                               const base::Closure& callback);
 
@@ skipping 39 matching lines @@
   void AllDone();
 
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(MalwareDetailsRedirectsCollector);
 };
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_MALWARE_DETAILS_HISTORY_H_