Fix Print Preview to System dialog bug

Update PrintJob::pdf_page_mapping_ so that PDF pages not in the
user's selection are ignored instead of causing the print job to be
cancelled.

Also remove some comments that are significantly outdated, and
caused confusion while investigating the bug.

Bug: 823876
Change-Id: Id6c1c3acb67c4d460cffa937f7a9b87eda402a88
Reviewed-on: https://chromium-review.googlesource.com/974042Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545173}

chrome/browser/printing/print_job.cc

@@ -85,6 +85,23 @@ void PrintJob::Initialize(PrintJobWorkerOwner* job,
                  content::Source<PrintJob>(this));
 }
 
+#if defined(OS_WIN)
+void PrintJob::ResetPageMapping() {
+  std::vector<int> pages = PageRange::GetPages(settings_.ranges());
+  if (pages.empty())
+    return;
+
+  pdf_page_mapping_ = std::vector<int>(document_->page_count(), -1);
+  for (int page_number : pages) {
+    // Make sure the page is in range.
+    if (page_number >= 0 &&
+        page_number < static_cast<int>(pdf_page_mapping_.size())) {
+      pdf_page_mapping_[page_number] = page_number;
+    }
+  }
+}
+#endif
+
 void PrintJob::Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) {
@@ -297,10 +314,14 @@ void PrintJob::OnPdfPageConverted(int page_number,
     return;
   }
 
-  // Update the rendered document. It will send notifications to the listener.
-  document_->SetPage(pdf_page_mapping_[page_number], std::move(metafile),
-                     scale_factor, pdf_conversion_state_->page_size(),
-                     pdf_conversion_state_->content_area());
+  // Add the page to the document if it is one of the pages requested by the
+  // user. If it is not, ignore it.
+  if (pdf_page_mapping_[page_number] != -1) {
+    // Update the rendered document. It will send notifications to the listener.
+    document_->SetPage(pdf_page_mapping_[page_number], std::move(metafile),
+                       scale_factor, pdf_conversion_state_->page_size(),
+                       pdf_conversion_state_->content_area());
+  }
 
   pdf_conversion_state_->GetMorePages(
       base::Bind(&PrintJob::OnPdfPageConverted, this));

chrome/browser/printing/print_job.h

@@ -53,6 +53,15 @@ class PrintJob : public PrintJobWorkerOwner,
                   const base::string16& name,
                   int page_count);
 
+#if defined(OS_WIN)
+  // Overwrites the PDF page mapping to fill in values of -1 for all indices
+  // that are not selected. This is needed when the user opens the system
+  // dialog from the link in Print Preview on Windows and then sets a selection
+  // of pages, because all PDF pages will be converted, but only the user's
+  // selected pages should be sent to the printer. See https://crbug.com/823876.
+  void ResetPageMapping();
+#endif
+
   // content::NotificationObserver implementation.
   void Observe(int type,
                const content::NotificationSource& source,

chrome/browser/printing/print_job_worker.cc

@@ -322,8 +322,7 @@ void PrintJobWorker::StartPrinting(PrintedDocument* new_document) {
     return;
   }
 
-  // Try to print already cached data. It may already have been generated for
-  // the print preview.
+  // This will start a loop to wait for the page data.
   OnNewPage();
   // Don't touch this anymore since the instance could be destroyed. It happens
   // if all the pages are printed a one sweep and the client doesn't have a

chrome/browser/printing/print_view_manager_base.cc

@@ -263,6 +263,10 @@ void PrintViewManagerBase::StartLocalPrintJob(
     return;
   }
 
+#if defined(OS_WIN)
+  print_job_->ResetPageMapping();
+#endif
+
   const printing::PrintSettings& settings = printer_query->settings();
   gfx::Size page_size = settings.page_setup_device_units().physical_size();
   gfx::Rect content_area =
@@ -578,8 +582,6 @@ bool PrintViewManagerBase::CreateNewPrintJob(PrintJobWorkerOwner* job) {
     return false;
   }
 
-  // Ask the renderer to generate the print preview, create the print preview
-  // view and switch to it, initialize the printer and show the print dialog.
   DCHECK(!print_job_.get());
   DCHECK(job);
   if (!job)