[Print Preview]: Added code to support pdf fit to page functionality.

chrome/browser/ui/webui/print_preview/print_preview_ui.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINT_PREVIEW_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINT_PREVIEW_UI_H_
 #pragma once
 
 #include <string>
 
@@ skipping 122 matching lines @@
 
   // Hides the print preview tab.
   void OnHidePreviewTab();
 
   // Closes the print preview tab.
   void OnClosePrintPreviewTab();
 
   // Reload the printers list.
   void OnReloadPrintersList();
 
+  // Notifies the WebUI that the pdf print scaling option is disabled by
+  // default.
+  void OnPrintPreviewScalingDisabled();
+
  private:
   friend class PrintPreviewHandlerTest;
   FRIEND_TEST_ALL_PREFIXES(PrintPreviewHandlerTest, StickyMarginsCustom);
   FRIEND_TEST_ALL_PREFIXES(PrintPreviewHandlerTest, StickyMarginsDefault);
   FRIEND_TEST_ALL_PREFIXES(PrintPreviewHandlerTest,
                            StickyMarginsCustomThenDefault);
   FRIEND_TEST_ALL_PREFIXES(PrintPreviewHandlerTest,
                            GetLastUsedMarginSettingsCustom);
   FRIEND_TEST_ALL_PREFIXES(PrintPreviewHandlerTest,
                            GetLastUsedMarginSettingsDefault);
@@ skipping 25 matching lines @@
   // Keeps track of whether OnClosePrintPreviewTab() has been called or not.
   bool tab_closed_;
 
   // True if the user visited the page directly, false if it's a live UI.
   bool is_dummy_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINT_PREVIEW_UI_H_