Ensure N-up PDF conversion failures notify Print Preview UI

From crbug.com/1000936, failures in doing conversion of PDF for N-up
caused the Print Preview UI to endlessly spin in the
"Loading preview ..." state without ever showing that it had failed.

Wrap the N-up conversion calls' callbacks with
mojo::WrapCallbackWithDefaultInvokeIfNotRun() so that a status is
provided even if the utility process disappears before completing.

Update the OnN-up<something>Done() callbacks to include a notification
call to the Print Preview UI to report errors.

Bug: 1003171
Change-Id: Ifd3b249196256b6186569d5a41b10ea39763f1dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1823801Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Alan Screen <awscreen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699958}

chrome/browser/printing/print_preview_message_handler.cc

@@ -31,6 +31,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
+#include "mojo/public/cpp/bindings/callback_helpers.h"
 #include "printing/nup_parameters.h"
 #include "printing/page_setup.h"
 #include "printing/print_job_constants.h"
@@ -353,8 +354,12 @@ void PrintPreviewMessageHandler::OnCompositePdfPageDone(
       client->DoNupPdfConvert(
           document_cookie, pages_per_sheet, print_preview_ui->page_size(),
           printable_area, std::move(pdf_page_regions),
-          base::BindOnce(&PrintPreviewMessageHandler::OnNupPdfConvertDone,
-                         weak_ptr_factory_.GetWeakPtr(), new_page_number, ids));
+          mojo::WrapCallbackWithDefaultInvokeIfNotRun(
+              base::BindOnce(&PrintPreviewMessageHandler::OnNupPdfConvertDone,
+                             weak_ptr_factory_.GetWeakPtr(), new_page_number,
+                             ids),
+              mojom::PdfNupConverter::Status::CONVERSION_FAILURE,
+              base::ReadOnlySharedMemoryRegion()));
     }
   }
 }
@@ -365,12 +370,14 @@ void PrintPreviewMessageHandler::OnNupPdfConvertDone(
     mojom::PdfNupConverter::Status status,
     base::ReadOnlySharedMemoryRegion region) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  PrintPreviewUI* print_preview_ui = GetPrintPreviewUI(ids.ui_id);
   if (status != mojom::PdfNupConverter::Status::SUCCESS) {
     DLOG(ERROR) << "Nup pdf page conversion failed with error " << status;
+    if (print_preview_ui)
+      print_preview_ui->OnPrintPreviewFailed(ids.request_id);
     return;
   }
 
-  PrintPreviewUI* print_preview_ui = GetPrintPreviewUI(ids.ui_id);
   if (!print_preview_ui)
     return;
 
@@ -412,10 +419,13 @@ void PrintPreviewMessageHandler::OnCompositePdfDocumentDone(
     client->DoNupPdfDocumentConvert(
         document_cookie, pages_per_sheet, print_preview_ui->page_size(),
         printable_area, std::move(region),
-        base::BindOnce(&PrintPreviewMessageHandler::OnNupPdfDocumentConvertDone,
-                       weak_ptr_factory_.GetWeakPtr(),
-                       (page_count + pages_per_sheet - 1) / pages_per_sheet,
-                       ids));
+        mojo::WrapCallbackWithDefaultInvokeIfNotRun(
+            base::BindOnce(
+                &PrintPreviewMessageHandler::OnNupPdfDocumentConvertDone,
+                weak_ptr_factory_.GetWeakPtr(),
+                (page_count + pages_per_sheet - 1) / pages_per_sheet, ids),
+            mojom::PdfNupConverter::Status::CONVERSION_FAILURE,
+            base::ReadOnlySharedMemoryRegion()));
   }
 }
 
@@ -425,12 +435,14 @@ void PrintPreviewMessageHandler::OnNupPdfDocumentConvertDone(
     mojom::PdfNupConverter::Status status,
     base::ReadOnlySharedMemoryRegion region) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  PrintPreviewUI* print_preview_ui = GetPrintPreviewUI(ids.ui_id);
   if (status != mojom::PdfNupConverter::Status::SUCCESS) {
     DLOG(ERROR) << "Nup pdf document convert failed with error " << status;
+    if (print_preview_ui)
+      print_preview_ui->OnPrintPreviewFailed(ids.request_id);
     return;
   }
 
-  PrintPreviewUI* print_preview_ui = GetPrintPreviewUI(ids.ui_id);
   if (!print_preview_ui)
     return;