Prevent a browser crash if dialogs are shown when navigating away.

chrome/browser/ui/browser_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
@@ skipping 453 matching lines @@
 }
 
 // Test for crbug.com/297289.  Ensure that modal dialogs are closed when a
 // cross-process navigation is ready to commit.
 IN_PROC_BROWSER_TEST_F(BrowserTest, CrossProcessNavCancelsDialogs) {
   ASSERT_TRUE(test_server()->Start());
   host_resolver()->AddRule("www.example.com", "127.0.0.1");
   GURL url(test_server()->GetURL("empty.html"));
   ui_test_utils::NavigateToURL(browser(), url);
 
+  // TODO(creis): Test this with a setInterval loop of alert dialogs to ensure
+  // that we can navigate away even if the renderer tries to synchronously
+  // create more.  See http://crbug.com/312490.
   WebContents* contents = browser()->tab_strip_model()->GetActiveWebContents();
   contents->GetRenderViewHost()->ExecuteJavascriptInWebFrame(
       string16(),
       ASCIIToUTF16("alert('Dialog showing!');"));
   AppModalDialog* alert = ui_test_utils::WaitForAppModalDialog();
   EXPECT_TRUE(alert->IsValid());
   AppModalDialogQueue* dialog_queue = AppModalDialogQueue::GetInstance();
   EXPECT_TRUE(dialog_queue->HasActiveDialog());
 
   // A cross-site navigation should force the dialog to close.
@@ skipping 2018 matching lines @@
   exp_commit_size.Enlarge(wcv_resize_insets.width(),
                           wcv_resize_insets.height() + height_inset);
   EXPECT_EQ(exp_commit_size, rwhv_commit_size2);
   EXPECT_EQ(exp_commit_size, wcv_commit_size2);
   // Sizes of RenderWidgetHostView and WebContentsView before and after
   // WebContentsDelegate::DidNavigateMainFramePostCommit should be the same.
   EXPECT_EQ(rwhv_commit_size2,
             web_contents->GetRenderWidgetHostView()->GetViewBounds().size());
   EXPECT_EQ(wcv_commit_size2, web_contents->GetView()->GetContainerSize());
 }