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

chrome/browser/printing/print_preview_message_handler.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/printing/print_preview_message_handler.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
@@ skipping 196 matching lines @@
 }
 
 void PrintPreviewMessageHandler::OnInvalidPrinterSettings(int document_cookie) {
   StopWorker(document_cookie);
   PrintPreviewUI* print_preview_ui = GetPrintPreviewUI();
   if (!print_preview_ui)
     return;
   print_preview_ui->OnInvalidPrinterSettings();
 }
 
+void PrintPreviewMessageHandler::OnPrintPreviewScalingDisabled() {
+  PrintPreviewUI* print_preview_ui = GetPrintPreviewUI();
+  if (!print_preview_ui)
+    return;
+  print_preview_ui->OnPrintPreviewScalingDisabled();
+}
+
 bool PrintPreviewMessageHandler::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintPreviewMessageHandler, message)
     IPC_MESSAGE_HANDLER(PrintHostMsg_RequestPrintPreview,
                         OnRequestPrintPreview)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPreviewPageCount,
                         OnDidGetPreviewPageCount)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidPreviewPage,
                         OnDidPreviewPage)
     IPC_MESSAGE_HANDLER(PrintHostMsg_MetafileReadyForPrinting,
                         OnMetafileReadyForPrinting)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewFailed,
                         OnPrintPreviewFailed)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetDefaultPageLayout,
                         OnDidGetDefaultPageLayout)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewCancelled,
                         OnPrintPreviewCancelled)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewInvalidPrinterSettings,
                         OnInvalidPrinterSettings)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewScalingDisabled,
+                        OnPrintPreviewScalingDisabled)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void PrintPreviewMessageHandler::NavigateToPendingEntry(
     const GURL& url,
     NavigationController::ReloadType reload_type) {
   TabContentsWrapper* tab = tab_contents_wrapper();
   TabContentsWrapper* preview_tab = GetPrintPreviewTab();
   if (tab == preview_tab) {
     // Cloud print sign-in reloads the page.
     DCHECK(PrintPreviewTabController::IsPrintPreviewURL(url));
     DCHECK_EQ(NavigationController::RELOAD, reload_type);
     return;
   }
   // If |tab| is navigating and it has a print preview tab, notify |tab| to
   // consider print preview done so it unfreezes the renderer in the case of
   // window.print().
   if (preview_tab)
     tab->print_view_manager()->PrintPreviewDone();
 }
 
 }  // namespace printing