Re-add backspace-goes-back as a default disabled finch trial

chrome/browser/ui/views/constrained_window_views_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 <memory>
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
@@ skipping 150 matching lines @@
   chrome::CloseWindow(browser());
   content::RunAllPendingInMessageLoop();
   EXPECT_TRUE(dialog->GetWidget()->IsVisible());
 
   // Close the dialog's browser window.
   chrome::CloseTab(browser2);
   content::RunAllPendingInMessageLoop();
   EXPECT_EQ(NULL, dialog->GetWidget());
 }
 
+// Tests that the web contents navigates when backspace is pressed.
+IN_PROC_BROWSER_TEST_F(ConstrainedWindowViewTest, NavigationOnBackspace) {
+  content::WebContents* web_contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+  content::WaitForLoadStop(web_contents);
+  const GURL original_url = web_contents->GetURL();
+  EXPECT_NE(GURL(chrome::kChromeUIVersionURL), original_url);
+  ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIVersionURL));
+  content::WaitForLoadStop(web_contents);
+  EXPECT_EQ(GURL(chrome::kChromeUIVersionURL), web_contents->GetURL());
+
+  std::unique_ptr<TestDialog> dialog = ShowModalDialog(web_contents);
+
+  views::Widget* widget = dialog->GetWidget();
+
+  EXPECT_TRUE(widget->IsVisible());
+  EXPECT_EQ(dialog->GetContentsView(),
+            widget->GetFocusManager()->GetFocusedView());
+
+  // Pressing backspace should not navigate back and close the dialog
+  // with the Finch flag disabled.
+  EXPECT_TRUE(chrome::CanGoBack(browser()));
+  EXPECT_TRUE(ui_test_utils::SendKeyPressSync(browser(), ui::VKEY_BACK,
+                                              false, false, false, false));
+  content::RunAllPendingInMessageLoop();
+  content::WaitForLoadStop(web_contents);
+
+  EXPECT_EQ(widget, dialog->GetWidget());
+  EXPECT_EQ(GURL(chrome::kChromeUIVersionURL), web_contents->GetURL());
+
+  // Pressing backspace should navigate back and close the dialog with the
+  // Finch flag enabled.
+  base::FeatureList::ClearInstanceForTesting();
+  std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->InitializeFromCommandLine("BackspaceGoesBack", std::string());
+  base::FeatureList::SetInstance(std::move(feature_list));
+
+  EXPECT_TRUE(chrome::CanGoBack(browser()));
+  EXPECT_TRUE(ui_test_utils::SendKeyPressSync(browser(), ui::VKEY_BACK,
+                                              false, false, false, false));
+  content::RunAllPendingInMessageLoop();
+  content::WaitForLoadStop(web_contents);
+
+  EXPECT_EQ(nullptr, dialog->GetWidget());
+  EXPECT_EQ(original_url, web_contents->GetURL());
+}
+
 // Tests that the dialog closes when the escape key is pressed.
 IN_PROC_BROWSER_TEST_F(ConstrainedWindowViewTest, ClosesOnEscape) {
 #if defined(OS_WIN)
   // TODO(msw): The widget is not made NULL on XP. http://crbug.com/177482
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return;
 #endif
 
   std::unique_ptr<TestDialog> dialog =
       ShowModalDialog(browser()->tab_strip_model()->GetActiveWebContents());
   EXPECT_TRUE(dialog->GetWidget()->IsVisible());
   EXPECT_TRUE(ui_test_utils::SendKeyPressSync(browser(), ui::VKEY_ESCAPE,
                                               false, false, false, false));
   content::RunAllPendingInMessageLoop();
   EXPECT_EQ(NULL, dialog->GetWidget());
 }