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

chrome/common/render_messages_internal.h

Index: chrome/common/render_messages_internal.h
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index fc449b8a681ace7a02b3559e3cad37303f5ef016..32e7528a79234f6d37c9c448c3561ed8bc599611 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -131,7 +131,8 @@ IPC_MESSAGE_ROUTED0(ViewMsg_PrintNodeUnderContextMenu)
 
 // Tells the renderer to print the print preview tab's PDF plugin without
 // showing the print dialog.
-IPC_MESSAGE_ROUTED0(ViewMsg_PrintForPrintPreview)
+IPC_MESSAGE_ROUTED1(ViewMsg_PrintForPrintPreview,
+                    std::string /* job_settings*/)
 
 // Tells the render view to close.
 IPC_MESSAGE_ROUTED0(ViewMsg_Close)
@@ -1707,6 +1708,18 @@ IPC_MESSAGE_ROUTED1(ViewHostMsg_DidPrintPage,
 IPC_SYNC_MESSAGE_ROUTED0_1(ViewHostMsg_GetDefaultPrintSettings,
                            ViewMsg_Print_Params /* default_settings */)
 
+// The renderer wants to know the current print settings.
+IPC_SYNC_MESSAGE_ROUTED1_1(ViewHostMsg_GetCurrentPrintSettings,
+                           int /* document_cookie */,
+                           ViewMsg_Print_Params /* current_settings */)
+
+// The renderer wants to update the current print settings with new
+// |job_settings|.
+IPC_SYNC_MESSAGE_ROUTED2_1(ViewHostMsg_UpdatePrintSettings,
+                           int /* document_cookie */,
+                           std::string /* job_settings */,
+                           ViewMsg_Print_Params /* current_settings */)
+
 // It's the renderer that controls the printing process when it is generated
 // by javascript. This step is about showing UI to the user to select the
 // final print settings. The output parameter is the same as