Remove bad CallJavascriptFunctionUnsafe call from PrintPreviewUI

"cancelPendingPrintRequest" does not actually exist. Remove the call to
this function from the PrintPreviewUI.

BUG=740264

Review-Url: https://codereview.chromium.org/2974183002
Cr-Commit-Position: refs/heads/master@{#485982}

chrome/browser/printing/background_printing_manager.cc

@@ -113,6 +113,11 @@ void BackgroundPrintingManager::DeletePreviewContentsForBrowserContext(
   }
 }
 
+void BackgroundPrintingManager::OnPrintRequestCancelled(
+    WebContents* preview_contents) {
+  DeletePreviewContents(preview_contents);
+}
+
 void BackgroundPrintingManager::DeletePreviewContents(
     WebContents* preview_contents) {
   auto i = printing_contents_map_.find(preview_contents);

chrome/browser/printing/background_printing_manager.h

@@ -48,6 +48,8 @@ class BackgroundPrintingManager : public content::NotificationObserver {
   void DeletePreviewContentsForBrowserContext(
       content::BrowserContext* browser_context);
 
+  void OnPrintRequestCancelled(content::WebContents* preview_dialog);
+
  private:
   // content::NotificationObserver overrides:
   void Observe(int type,

chrome/browser/ui/webui/print_preview/print_preview_handler.cc

@@ -1594,6 +1594,10 @@ void PrintPreviewHandler::OnPrintPreviewCancelled() {
   preview_callbacks_.pop();
 }
 
+void PrintPreviewHandler::OnPrintRequestCancelled() {
+  HandleCancelPendingPrintRequest(nullptr);
+}
+
 #if BUILDFLAG(ENABLE_BASIC_PRINT_DIALOG)
 void PrintPreviewHandler::ShowSystemDialog() {
   HandleShowSystemDialog(NULL);

chrome/browser/ui/webui/print_preview/print_preview_handler.h

@@ -86,6 +86,9 @@ class PrintPreviewHandler
   // Called when print preview is ready.
   void OnPrintPreviewReady(int preview_uid, int request_id);
 
+  // Called when a print request is cancelled due to its initiator closing.
+  void OnPrintRequestCancelled();
+
   // Send the print preset options from the document.
   void SendPrintPresetOptions(bool disable_scaling, int copies, int duplex);
 

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

@@ -533,13 +533,20 @@ void PrintPreviewUI::OnPrintPreviewDialogClosed() {
 }
 
 void PrintPreviewUI::OnInitiatorClosed() {
+  // Should only get here if the initiator was still tracked by the Print
+  // Preview Dialog Controller, so the print job has not yet been sent.
   WebContents* preview_dialog = web_ui()->GetWebContents();
   printing::BackgroundPrintingManager* background_printing_manager =
       g_browser_process->background_printing_manager();
-  if (background_printing_manager->HasPrintPreviewDialog(preview_dialog))
-    web_ui()->CallJavascriptFunctionUnsafe("cancelPendingPrintRequest");
-  else
+  if (background_printing_manager->HasPrintPreviewDialog(preview_dialog)) {
+    // Dialog is hidden but is still generating the preview. Cancel the print
+    // request as it can't be completed.
+    background_printing_manager->OnPrintRequestCancelled(preview_dialog);
+    handler_->OnPrintRequestCancelled();
+  } else {
+    // Initiator was closed while print preview dialog was still open.
     OnClosePrintPreviewDialog();
+  }
 }
 
 void PrintPreviewUI::OnPrintPreviewCancelled() {