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

chrome/browser/printing/print_preview_message_handler.cc

Index: chrome/browser/printing/print_preview_message_handler.cc
diff --git a/chrome/browser/printing/print_preview_message_handler.cc b/chrome/browser/printing/print_preview_message_handler.cc
index 7dd0a962918fb5703d6c311177089ee659bc87e9..e7c8c25d90c120c94d40cacf27e144fb9156ecdc 100644
--- a/chrome/browser/printing/print_preview_message_handler.cc
+++ b/chrome/browser/printing/print_preview_message_handler.cc
@@ -24,6 +24,7 @@
 #include "content/public/browser/web_ui.h"
 #include "printing/page_size_margins.h"
 #include "printing/print_job_constants.h"
+#include "ui/gfx/rect.h"
 
 using content::BrowserThread;
 using content::NavigationController;
@@ -214,6 +215,16 @@ void PrintPreviewMessageHandler::OnInvalidPrinterSettings(int document_cookie) {
   print_preview_ui->OnInvalidPrinterSettings();
 }
 
+void PrintPreviewMessageHandler::OnPrintPreviewScalingDisabled() {
+  TabContentsWrapper* print_preview_tab = GetPrintPreviewTab();
+  if (!print_preview_tab || !print_preview_tab->web_contents()->GetWebUI())
+    return;
+
+  PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(
+      print_preview_tab->web_contents()->GetWebUI()->GetController());
+  print_preview_ui->OnPrintPreviewScalingDisabled();
+}
+
 bool PrintPreviewMessageHandler::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
@@ -234,6 +245,8 @@ bool PrintPreviewMessageHandler::OnMessageReceived(
                         OnPrintPreviewCancelled)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewInvalidPrinterSettings,
                         OnInvalidPrinterSettings)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewScalingDisabled,
+                        OnPrintPreviewScalingDisabled)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;