Added functionality to use "SaveAs..." from PDF plugin.

chrome/browser/ui/download/download_tab_helper.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_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "chrome/browser/download/save_package.h"
+#include "content/browser/tab_contents/tab_contents_observer.h"
 
 // Per-tab download controller. Handles dealing with various per-tab download
 // duties.
-class DownloadTabHelper {
+class DownloadTabHelper : public TabContentsObserver {
  public:
   explicit DownloadTabHelper(TabContents* tab_contents);
   virtual ~DownloadTabHelper();
 
   // Prepare for saving the current web page to disk.
   void OnSavePage();
 
   // Save page with the main HTML file path, the directory for saving resources,
   // and the save type: HTML only or complete web page. Returns true if the
   // saving process has been initiated successfully.
   bool SavePage(const FilePath& main_file, const FilePath& dir_path,
                 SavePackage::SavePackageType save_type);
 
   // Returns the SavePackage which manages the page saving job. May be NULL.
   SavePackage* save_package() const { return save_package_.get(); }
 
  private:
-  TabContents* tab_contents_;
+  // TabContentsObserver overrides.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // SavePackage, lazily created.
   scoped_refptr<SavePackage> save_package_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_H_