Cleanup: Remove forward declarations in various chrome/browser directories.

chrome/browser/printing/print_preview_tab_controller.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.
 
 // For print preview, a print preview (PP) tab is linked with the initiator tab
 // that initiated the printing operation. If the tab initiates a second
 // printing operation while the first print preview tab is still open, that PP
 // tab is focused/activated. There may be more than one PP tab open. There is a
 // 1:1 relationship between PP tabs and initiating tabs. This class manages PP
 // tabs and initiator tabs.
 #ifndef CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
 
 #define CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
 #pragma once
 
 #include <map>
 
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
-class Browser;
 class GURL;
 class RenderProcessHost;
 class TabContentsWrapper;
 
 namespace content {
 struct LoadCommittedDetails;
 }
 
 namespace printing {
 
@@ skipping 79 matching lines @@
   // True if the controller is waiting for a new preview tab via
   // content::NAVIGATION_TYPE_NEW_PAGE.
   bool waiting_for_new_preview_page_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewTabController);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_