Move prefs-related files under chrome/browser/ into a prefs/ subdir.

chrome/browser/cocoa/custom_home_pages_model.mm

 // Copyright (c) 2010 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.
 
 #import "chrome/browser/cocoa/custom_home_pages_model.h"
 
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/net/url_fixer_upper.h"
-#include "chrome/browser/session_startup_pref.h"
+#include "chrome/browser/prefs/session_startup_pref.h"
 
 NSString* const kHomepageEntryChangedNotification =
     @"kHomepageEntryChangedNotification";
 
 @interface CustomHomePagesModel (Private)
 - (void)setURLsInternal:(const std::vector<GURL>&)urls;
 @end
 
 @implementation CustomHomePagesModel
 
@@ skipping 111 matching lines @@
 
 - (NSImage*)image {
   return icon_.get();
 }
 
 - (NSString*)description {
   return url_.get();
 }
 
 @end