PrintPreview: Preview generation should not block print button.

chrome/renderer/print_web_view_helper.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 182 matching lines @@
     return;
   WebFrame* main_frame = render_view()->webview()->mainFrame();
   if (!main_frame)
     return;
 
   WebDocument document = main_frame->document();
   // <object> with id="pdf-viewer" is created in
   // chrome/browser/resources/print_preview.js
   WebElement pdf_element = document.getElementById("pdf-viewer");
   if (pdf_element.isNull()) {
-    NOTREACHED();
+    DidFinishPrinting(FAIL_PRINT);

[Lei Zhang, 2011/06/09 09:54:55]

Can you explain how we reach this state? It seems this means there's no PDF
plugin, but we tried to print anyway. Why would we ever do that?

[kmadhusu, 2011/06/09 18:11:44]

While testing I came across a test case which satisfied this condition. Now I
don't remember the scenario exactly. I am reverting this changes. If required we
can handle this later.

     return;
   }
 
   WebFrame* pdf_frame = pdf_element.document().frame();
   if (!InitPrintSettings(pdf_frame, &pdf_element)) {
     NOTREACHED() << "Failed to initialize print page settings";
     return;
   }
 
   if (!UpdatePrintSettings(job_settings)) {
@@ skipping 140 matching lines @@
 void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
   if (result == FAIL_PRINT) {
     WebView* web_view = print_web_view_;
     if (!web_view)
       web_view = render_view()->webview();
 
     render_view()->runModalAlertDialog(
         web_view->mainFrame(),
         l10n_util::GetStringUTF16(IDS_PRINT_SPOOL_FAILED_ERROR_TEXT));
 
-    if (notify_browser_of_print_failure_) {
+    if (notify_browser_of_print_failure_ && print_pages_params_.get()) {
       int cookie = print_pages_params_->params.document_cookie;
       Send(new PrintHostMsg_PrintingFailed(routing_id(), cookie));
     }
   } else if (result == FAIL_PREVIEW) {
     int cookie = print_pages_params_->params.document_cookie;
     Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
   }
 
   if (print_web_view_) {
     print_web_view_->close();
@@ skipping 369 matching lines @@
 
 void PrintWebViewHelper::ResetScriptedPrintCount() {
   // Reset cancel counter on successful print.
   user_cancelled_scripted_print_count_ = 0;
 }
 
 void PrintWebViewHelper::IncrementScriptedPrintCount() {
   ++user_cancelled_scripted_print_count_;
   last_cancelled_script_print_ = base::Time::Now();
 }