Fix print preview workflow to reflect settings of selected printer.

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 9a5d2f44eeb4164068243395a05df74402869c51..869e742a1423640d660235622deaf83402854136 100644
--- a/chrome/renderer/mock_printer.cc
+++ b/chrome/renderer/mock_printer.cc
@@ -123,8 +123,9 @@ void MockPrinter::ScriptedPrint(int cookie,
 void MockPrinter::UpdateSettings(int cookie,
                                  PrintMsg_PrintPages_Params* params,
                                  const std::vector<int>& pages) {
-  EXPECT_EQ(document_cookie_, cookie);
-
+  if (document_cookie_ == -1) {
+    document_cookie_ = CreateDocumentCookie();
+  }
   params->Reset();
   params->pages = pages;
   SetPrintParams(&(params->params));