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 88ff1df821dec0dd71d3159a41a1ce8e746aca69..a429695b031487c00a727e9263805da6dfdca9df 100644
--- a/chrome/browser/renderer_host/render_view_host.h
+++ b/chrome/browser/renderer_host/render_view_host.h
@@ -329,6 +329,10 @@ class RenderViewHost : public RenderWidgetHost {
   // Prints the node that's under the context menu.
   void PrintNodeUnderContextMenu();
 
+  // 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);