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

chrome/browser/dom_ui/print_preview_handler.cc

Index: chrome/browser/dom_ui/print_preview_handler.cc
diff --git a/chrome/browser/dom_ui/print_preview_handler.cc b/chrome/browser/dom_ui/print_preview_handler.cc
index 80e53fbac52c0b4d347b656ac135ee5ea69d93ec..f24a9ddfe83065e4597c71293abf8946034ef0a9 100644
--- a/chrome/browser/dom_ui/print_preview_handler.cc
+++ b/chrome/browser/dom_ui/print_preview_handler.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/dom_ui/print_preview_handler.h"
 
 #include "base/values.h"
+#include "chrome/browser/dom_ui/web_ui_util.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
 #include "printing/backend/print_backend.h"
 
 PrintPreviewHandler::PrintPreviewHandler()
@@ -17,6 +19,8 @@ PrintPreviewHandler::~PrintPreviewHandler() {
 void PrintPreviewHandler::RegisterMessages() {
   web_ui_->RegisterMessageCallback("getPrinters",
       NewCallback(this, &PrintPreviewHandler::HandleGetPrinters));
+  web_ui_->RegisterMessageCallback("print",
+      NewCallback(this, &PrintPreviewHandler::HandlePrint));
 }
 
 void PrintPreviewHandler::HandleGetPrinters(const ListValue*) {
@@ -31,3 +35,13 @@ void PrintPreviewHandler::HandleGetPrinters(const ListValue*) {
 
   web_ui_->CallJavascriptFunction(L"setPrinters", printers);
 }
+
+void PrintPreviewHandler::HandlePrint(const ListValue* args) {
+  std::string json_str(
+      web_ui_util::GetJsonResponseFromFirstArgumentInList(args));
+  if (json_str.empty()) {
+    NOTREACHED() << "Empty print job settings";
+    return;
+  }
+  web_ui_->GetRenderViewHost()->PrintForPrintPreview(json_str);
+}