Print Preview: Hook up the print button to initiate printing without displaying a print dialog.

chrome/browser/printing/print_job_worker.h

Index: chrome/browser/printing/print_job_worker.h
diff --git a/chrome/browser/printing/print_job_worker.h b/chrome/browser/printing/print_job_worker.h
index 6b0183b64423a4dd7e175b364772ddaaed826f1d..bb4820a3badbc7f4a6222feb39fe7314a098bf10 100644
--- a/chrome/browser/printing/print_job_worker.h
+++ b/chrome/browser/printing/print_job_worker.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -42,6 +42,9 @@ class PrintJobWorker : public base::Thread {
                    bool has_selection,
                    bool use_overlays);
 
+  // Set the new print settings. |new_settings| is a json string.
+  void SetSettings(const std::string& new_settings);
+
   // Starts the printing loop. Every pages are printed as soon as the data is
   // available. Makes sure the new_document is the right one.
   void StartPrinting(PrintedDocument* new_document);
@@ -92,6 +95,9 @@ class PrintJobWorker : public base::Thread {
   // back into the IO thread for GetSettingsDone().
   void GetSettingsWithUIDone(PrintingContext::Result result);
 
+  // Called on the UI thread to update the print settings.
+  void UpdatePrintSettings(const std::string& new_settings);
+
   // Reports settings back to owner_.
   void GetSettingsDone(PrintingContext::Result result);