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

chrome/browser/renderer_host/render_view_host.h

Index: chrome/browser/renderer_host/render_view_host.h
diff --git a/chrome/browser/renderer_host/render_view_host.h b/chrome/browser/renderer_host/render_view_host.h
index c5daa69977636a534fab90f6245366234bba5f75..7c2e035e963aabd3ff7c025d5e9774c0bbf09009 100644
--- a/chrome/browser/renderer_host/render_view_host.h
+++ b/chrome/browser/renderer_host/render_view_host.h
@@ -328,8 +328,9 @@ class RenderViewHost : public RenderWidgetHost {
   // Prints the node that's under the context menu.
   void PrintNodeUnderContextMenu();
 
-  // Triggers printing of the preview PDF.
-  void PrintForPrintPreview();
+  // Triggers printing of the preview PDF. |job_settings| is a json string that
+  // contains print job settings information.
+  void PrintForPrintPreview(const std::string& job_settings);
 
   // Copies the image at the specified point.
   void CopyImageAt(int x, int y);