Printing: Keep track of WebContents lifetime for the native printing UI.

chrome/browser/printing/print_job_worker.cc

Index: chrome/browser/printing/print_job_worker.cc
diff --git a/chrome/browser/printing/print_job_worker.cc b/chrome/browser/printing/print_job_worker.cc
index a3298f5998010f0ce44cea7ed1a7d507b0508516..66477b1beb1d220d00518d97098b6470b4a25375 100644
--- a/chrome/browser/printing/print_job_worker.cc
+++ b/chrome/browser/printing/print_job_worker.cc
@@ -13,6 +13,7 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/printing/print_job.h"
+#include "chrome/browser/printing/printing_ui_web_contents_observer.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "grit/generated_resources.h"
@@ -77,11 +78,12 @@ void PrintJobWorker::SetPrintDestination(
   destination_ = destination;
 }
 
-void PrintJobWorker::GetSettings(bool ask_user_for_settings,
-                                 gfx::NativeView parent_view,
-                                 int document_page_count,
-                                 bool has_selection,
-                                 MarginType margin_type) {
+void PrintJobWorker::GetSettings(
+    bool ask_user_for_settings,
+    scoped_ptr<PrintingUIWebContentsObserver> web_contents_observer,
+    int document_page_count,
+    bool has_selection,
+    MarginType margin_type) {
   DCHECK_EQ(message_loop(), base::MessageLoop::current());
   DCHECK_EQ(page_number_, PageNumber::npos());
 
@@ -100,8 +102,10 @@ void PrintJobWorker::GetSettings(bool ask_user_for_settings,
         BrowserThread::UI, FROM_HERE,
         base::Bind(&HoldRefCallback, make_scoped_refptr(owner_),
                    base::Bind(&PrintJobWorker::GetSettingsWithUI,
-                              base::Unretained(this), parent_view,
-                              document_page_count, has_selection)));
+                              base::Unretained(this),
+                              base::Passed(&web_contents_observer),
+                              document_page_count,
+                              has_selection)));
   } else {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
@@ -169,11 +173,17 @@ void PrintJobWorker::GetSettingsDone(PrintingContext::Result result) {
                  result));
 }
 
-void PrintJobWorker::GetSettingsWithUI(gfx::NativeView parent_view,
-                                       int document_page_count,
-                                       bool has_selection) {
+void PrintJobWorker::GetSettingsWithUI(
+    scoped_ptr<PrintingUIWebContentsObserver> web_contents_observer,
+    int document_page_count,
+    bool has_selection) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  gfx::NativeView parent_view = web_contents_observer->GetParentView();
+  if (!parent_view) {
+    GetSettingsWithUIDone(printing::PrintingContext::FAILED);
+    return;
+  }
   printing_context_->AskUserForSettings(
       parent_view, document_page_count, has_selection,
       base::Bind(&PrintJobWorker::GetSettingsWithUIDone,