Make The task manager browser tests for the print preview work under --site-per-process

chrome/browser/printing/print_preview_dialog_controller_browsertest.cc

Index: chrome/browser/printing/print_preview_dialog_controller_browsertest.cc
diff --git a/chrome/browser/printing/print_preview_dialog_controller_browsertest.cc b/chrome/browser/printing/print_preview_dialog_controller_browsertest.cc
index 932f80c6c4ea7ee082770768ee58774e5a7cf3c9..191e67403ce8ab3a888affadbdd1c0de0b94076e 100644
--- a/chrome/browser/printing/print_preview_dialog_controller_browsertest.cc
+++ b/chrome/browser/printing/print_preview_dialog_controller_browsertest.cc
@@ -373,7 +373,7 @@ IN_PROC_BROWSER_TEST_F(PrintPreviewDialogControllerBrowserTest,
   // Navigating away from the current page in the current tab for which a print
   // preview is displayed will cancel the print preview and hence the task
   // manger shouldn't show a printing task.
-  ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUINewTabURL));
+  ui_test_utils::NavigateToURL(browser(), GURL("about:blank"));
   EXPECT_EQ(2U, GetTrackedTags().size());
   EXPECT_EQ(2U, task_manager.tasks().size());