Remove the last usages of PrefObserver outside of Prefs.

chrome/browser/net/chrome_network_delegate.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/net/chrome_network_delegate.h"
 
 #include <vector>
 
 #include "base/base_paths.h"
 #include "base/logging.h"
@@ skipping 285 matching lines @@
   g_never_throttle_requests_ = true;
 }
 
 // static
 void ChromeNetworkDelegate::InitializePrefsOnUIThread(
     BooleanPrefMember* enable_referrers,
     BooleanPrefMember* enable_do_not_track,
     BooleanPrefMember* force_google_safe_search,
     PrefService* pref_service) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  enable_referrers->Init(prefs::kEnableReferrers, pref_service, NULL);
+  enable_referrers->Init(prefs::kEnableReferrers, pref_service);
   enable_referrers->MoveToThread(
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
   if (enable_do_not_track) {
-    enable_do_not_track->Init(prefs::kEnableDoNotTrack, pref_service, NULL);
+    enable_do_not_track->Init(prefs::kEnableDoNotTrack, pref_service);
     enable_do_not_track->MoveToThread(
         BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
   }
   if (force_google_safe_search) {
-    force_google_safe_search->Init(prefs::kForceSafeSearch, pref_service, NULL);
+    force_google_safe_search->Init(prefs::kForceSafeSearch, pref_service);
     force_google_safe_search->MoveToThread(
         BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
   }
 }
 
 // static
 void ChromeNetworkDelegate::AllowAccessToAllFiles() {
   g_allow_file_access_ = true;
 }
 
@@ skipping 329 matching lines @@
 
 void ChromeNetworkDelegate::AccumulateContentLength(
     int64 received_content_length, int64 original_content_length) {
   DCHECK_GE(received_content_length, 0);
   DCHECK_GE(original_content_length, 0);
   StoreAccumulatedContentLength(received_content_length,
                                 original_content_length);
   received_content_length_ += received_content_length;
   original_content_length_ += original_content_length;
 }