Print preview not showing if default print is invalid.

chrome/renderer/print_web_view_helper.cc

Index: chrome/renderer/print_web_view_helper.cc
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index f0fc8da7dde081f8b8afa64d30f70b6db8d2d019..7dd9bb8e6a3b5ff5d9302b5c68d02365dc13357b 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -629,8 +629,11 @@ void PrintWebViewHelper::OnPrintPreview(const DictionaryValue& settings) {
   print_preview_context_.OnPrintPreview();
 
   if (!InitPrintSettings(print_preview_context_.frame(),
-                         print_preview_context_.node())) {
-    NOTREACHED();
+                         print_preview_context_.node(),
+                         true)) {
+    Send(new PrintHostMsg_PrintPreviewInvalidDefaultPrinter(
+                 routing_id(),
+                 print_pages_params_->params.document_cookie));
     return;
   }
 
@@ -1009,7 +1012,8 @@ void PrintWebViewHelper::UpdatePrintableSizeInPrintParameters(
 }
 
 bool PrintWebViewHelper::InitPrintSettings(WebKit::WebFrame* frame,
-                                           WebKit::WebNode* node) {
+                                           WebKit::WebNode* node,
+                                           bool is_preview) {
   DCHECK(frame);
   PrintMsg_PrintPages_Params settings;
 
@@ -1019,9 +1023,11 @@ bool PrintWebViewHelper::InitPrintSettings(WebKit::WebFrame* frame,
   // can safely assume there are no printer drivers configured. So we safely
   // terminate.
   if (PrintMsg_Print_Params_IsEmpty(settings.params)) {
-    render_view()->runModalAlertDialog(
-        frame,
-        l10n_util::GetStringUTF16(IDS_DEFAULT_PRINTER_NOT_FOUND_WARNING));
+    if (!is_preview) {
+      render_view()->runModalAlertDialog(
+          frame,
+          l10n_util::GetStringUTF16(IDS_DEFAULT_PRINTER_NOT_FOUND_WARNING));
+    }
     return false;
   }
   if (settings.params.dpi < kMinDpi || settings.params.document_cookie == 0) {
@@ -1038,7 +1044,7 @@ bool PrintWebViewHelper::InitPrintSettings(WebKit::WebFrame* frame,
 bool PrintWebViewHelper::InitPrintSettingsAndPrepareFrame(
     WebKit::WebFrame* frame, WebKit::WebNode* node,
     scoped_ptr<PrepareFrameAndViewForPrint>* prepare) {
-  if (!InitPrintSettings(frame, node))
+  if (!InitPrintSettings(frame, node, false))
     return false;
 
   DCHECK(!prepare->get());