Use JS Date().toLocaleDateString() to format date in header.

chrome/renderer/mock_printer.cc

Index: chrome/renderer/mock_printer.cc
diff --git a/chrome/renderer/mock_printer.cc b/chrome/renderer/mock_printer.cc
index fdcbd0ee71fc8c620042442436951dae9d9b3f0f..d7a5c3ffe3885bebce57487f86397e11646087a2 100644
--- a/chrome/renderer/mock_printer.cc
+++ b/chrome/renderer/mock_printer.cc
@@ -72,7 +72,6 @@ MockPrinter::MockPrinter()
     preview_request_id_(0),
     print_scaling_option_(WebKit::WebPrintScalingOptionSourceSize),
     display_header_footer_(false),
-    date_(ASCIIToUTF16("date")),
     title_(ASCIIToUTF16("title")),
     url_(ASCIIToUTF16("url")),
     use_invalid_settings_(false) {
@@ -119,7 +118,6 @@ void MockPrinter::SetDefaultPrintSettings(const PrintMsg_Print_Params& params) {
   margin_left_ = params.margin_left;
   margin_top_ = params.margin_top;
   display_header_footer_ = params.display_header_footer;
-  date_ = params.date;
   title_ = params.title;
   url_ = params.url;
 }
@@ -162,7 +160,6 @@ void MockPrinter::ScriptedPrint(int cookie,
   settings->params.print_to_pdf = print_to_pdf_;
   settings->params.preview_request_id = preview_request_id_;
   settings->params.display_header_footer = display_header_footer_;
-  settings->params.date = date_;
   settings->params.title = title_;
   settings->params.url = url_;
   printer_status_ = PRINTER_PRINTING;
@@ -312,7 +309,6 @@ void MockPrinter::SetPrintParams(PrintMsg_Print_Params* params) {
   params->print_to_pdf = print_to_pdf_;
   params->preview_request_id = preview_request_id_;
   params->display_header_footer = display_header_footer_;
-  params->date = date_;
   params->title = title_;
   params->url = url_;
 }