Print preview not showing if default print is invalid.

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 3d1455911d9628cff9cc4550ee3ee14aa29ef782..6b639edcc238efd73b014586fa8dd61b9260f0c3 100644
--- a/chrome/renderer/mock_printer.cc
+++ b/chrome/renderer/mock_printer.cc
@@ -87,6 +87,10 @@ void MockPrinter::SetDefaultPrintSettings(const PrintMsg_Print_Params& params) {
   url_ = params.url;
 }
 
+void MockPrinter::SetBadSettings(bool be_evil) {

[kmadhusu, 2011/08/26 18:50:40]

How about UseInvalidSettings()? This function will always set
|use_invalid_settings_| to true. 

void MockPrinter::UseInvalidSettings() {
  use_invalid_settings_ = true;
}

[arthurhsu, 2011/08/29 22:53:16]

Added a value in parameter, since we need to flip the bit back for other test
cases.

+  evil_ = be_evil;
+}
+
 void MockPrinter::ScriptedPrint(int cookie,
                                 int expected_pages_count,
                                 bool has_selection,
@@ -236,7 +240,7 @@ bool MockPrinter::SaveBitmap(
 }
 
 int MockPrinter::CreateDocumentCookie() {
-  return ++current_document_cookie_;
+  return evil_ ? 0 : ++current_document_cookie_;

[kmadhusu, 2011/08/26 18:50:40]

document_cookie is not a printer setting. So its better to set "dpi"  or 
"page_size" or "printable_size" values to zero to represent invalid printer
settings.

[arthurhsu, 2011/08/29 22:53:16]

It is used to determine if the printer settings is invalid in
print_web_view_helper.cc:102.

 }
 
 void MockPrinter::SetPrintParams(PrintMsg_Print_Params* params) {