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

chrome/browser/net/net_pref_observer.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_NET_NET_PREF_OBSERVER_H_
 #define CHROME_BROWSER_NET_NET_PREF_OBSERVER_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "chrome/browser/prefs/pref_member.h"
 #include "content/public/browser/notification_observer.h"
 
-class Profile;
-
 namespace chrome_browser_net {
 class Predictor;
 }
 
 namespace prerender {
 class PrerenderManager;
 }
 
 // Monitors network-related preferences for changes and applies them.
 // The supplied PrefService must outlive this NetPrefObserver.
@@ skipping 22 matching lines @@
   BooleanPrefMember network_prediction_enabled_;
   BooleanPrefMember spdy_disabled_;
   BooleanPrefMember http_throttling_enabled_;
   prerender::PrerenderManager* prerender_manager_;
   chrome_browser_net::Predictor* predictor_;
 
   DISALLOW_COPY_AND_ASSIGN(NetPrefObserver);
 };
 
 #endif  // CHROME_BROWSER_NET_NET_PREF_OBSERVER_H_