Remove the BackspaceGoesBack flag.

This has shipped for months and won't be rolled back. We don't
need to keep this code around.

BUG=699133
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2865793002
Cr-Commit-Position: refs/heads/master@{#475637}
diff --git a/chrome/browser/resources/chromeos/keyboard_overlay.js b/chrome/browser/resources/chromeos/keyboard_overlay.js
index 86a3ab0..38cdf54 100644
--- a/chrome/browser/resources/chromeos/keyboard_overlay.js
+++ b/chrome/browser/resources/chromeos/keyboard_overlay.js
@@ -227,14 +227,6 @@
     delete shortcutDataCache['0<>CTRL<>SHIFT'];
   }
 
-  if (!loadTimeData.getBoolean('backspaceGoesBackFeatureEnabled')) {
-    // If the "backspace key goes back" experiment is not enabled, then we
-    // clear the shortcuts for Backspace and Shift+Backspace to go back or
-    // forward respectively.
-    delete shortcutDataCache['backspace'];
-    delete shortcutDataCache['backspace<>SHIFT'];
-  }
-
   return shortcutDataCache;
 }
 
diff --git a/chrome/browser/resources/chromeos/keyboard_overlay_data.js b/chrome/browser/resources/chromeos/keyboard_overlay_data.js
index 352b929..40095ad 100644
--- a/chrome/browser/resources/chromeos/keyboard_overlay_data.js
+++ b/chrome/browser/resources/chromeos/keyboard_overlay_data.js
@@ -15811,12 +15811,10 @@
     'b<>CTRL<>SHIFT': 'keyboardOverlayToggleBookmarkBar',
     'back<>CTRL': 'keyboardOverlayFocusPreviousPane',
     'back<>SEARCH': 'keyboardOverlayF1',
-    'backspace': 'keyboardOverlayGoBack',
     'backspace<>ALT': 'keyboardOverlayDelete',
     'backspace<>CTRL': 'keyboardOverlayDeleteWord',
     'backspace<>CTRL<>SHIFT': 'keyboardOverlayClearBrowsingDataDialog',
     'backspace<>SEARCH': 'keyboardOverlayDelete',
-    'backspace<>SHIFT': 'keyboardOverlayGoForward',
     'bright down<>ALT': 'keyboardOverlayDecreaseKeyBrightness',
     'bright down<>ALT<>CTRL': 'keyboardOverlayMagnifierDecreaseZoom',
     'bright down<>SEARCH': 'keyboardOverlayF6',
diff --git a/chrome/browser/ui/browser_command_controller.cc b/chrome/browser/ui/browser_command_controller.cc
index 7db71e1..7486eea 100644
--- a/chrome/browser/ui/browser_command_controller.cc
+++ b/chrome/browser/ui/browser_command_controller.cc
@@ -11,7 +11,6 @@
 #include "base/command_line.h"
 #include "base/debug/debugging_flags.h"
 #include "base/debug/profiler.h"
-#include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/metrics/user_metrics.h"
 #include "build/build_config.h"
@@ -37,7 +36,6 @@
 #include "chrome/browser/ui/chrome_pages.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/webui/inspect_ui.h"
-#include "chrome/common/chrome_features.h"
 #include "chrome/common/content_restriction.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/profiling.h"
@@ -308,20 +306,14 @@
   switch (id) {
     // Navigation commands
     case IDC_BACKSPACE_BACK:
-      if (base::FeatureList::IsEnabled(features::kBackspaceGoesBackFeature))
-        GoBack(browser_, disposition);
-      else
-        window()->MaybeShowNewBackShortcutBubble(false);
+      window()->MaybeShowNewBackShortcutBubble(false);
       break;
     case IDC_BACK:
       window()->HideNewBackShortcutBubble();
       GoBack(browser_, disposition);
       break;
     case IDC_BACKSPACE_FORWARD:
-      if (base::FeatureList::IsEnabled(features::kBackspaceGoesBackFeature))
-        GoForward(browser_, disposition);
-      else
-        window()->MaybeShowNewBackShortcutBubble(true);
+      window()->MaybeShowNewBackShortcutBubble(true);
       break;
     case IDC_FORWARD:
       window()->HideNewBackShortcutBubble();
diff --git a/chrome/browser/ui/views/constrained_window_views_browsertest.cc b/chrome/browser/ui/views/constrained_window_views_browsertest.cc
index 5db441f..5538e47 100644
--- a/chrome/browser/ui/views/constrained_window_views_browsertest.cc
+++ b/chrome/browser/ui/views/constrained_window_views_browsertest.cc
@@ -5,14 +5,11 @@
 #include <memory>
 
 #include "base/macros.h"
-#include "base/test/scoped_feature_list.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/views/tab_modal_confirm_dialog_views.h"
-#include "chrome/common/chrome_features.h"
-#include "chrome/common/url_constants.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/interactive_test_utils.h"
 #include "chrome/test/base/ui_test_utils.h"
@@ -170,51 +167,6 @@
   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::test::ScopedFeatureList scoped_feature_list;
-  scoped_feature_list.InitAndEnableFeature(features::kBackspaceGoesBackFeature);
-
-  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)
diff --git a/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc b/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
index ae29d00..59a7300 100644
--- a/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
@@ -10,14 +10,12 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
-#include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/profiles/profile.h"
-#include "chrome/common/chrome_features.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/browser_resources.h"
@@ -316,9 +314,6 @@
   display::DisplayManager* display_manager = shell->display_manager();
   source->AddBoolean("keyboardOverlayIsDisplayUIScalingEnabled",
                      display_manager->IsDisplayUIScalingEnabled());
-  source->AddBoolean(
-      "backspaceGoesBackFeatureEnabled",
-      base::FeatureList::IsEnabled(features::kBackspaceGoesBackFeature));
   source->SetJsonPath("strings.js");
   source->AddResourcePath("keyboard_overlay.js", IDR_KEYBOARD_OVERLAY_JS);
   source->SetDefaultResource(IDR_KEYBOARD_OVERLAY_HTML);
diff --git a/chrome/common/chrome_features.cc b/chrome/common/chrome_features.cc
index 4181b41..7e8134d0 100644
--- a/chrome/common/chrome_features.cc
+++ b/chrome/common/chrome_features.cc
@@ -60,12 +60,6 @@
     "BackgroundModeAllowRestart", base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_WIN) || defined(OS_LINUX)
 
-// Enables the Backspace key to navigate back in the browser, as well as
-// Shift+Backspace to navigate forward.
-const base::Feature kBackspaceGoesBackFeature {
-  "BackspaceGoesBack", base::FEATURE_DISABLED_BY_DEFAULT
-};
-
 // Enables or disables whether permission prompts are automatically blocked
 // after the user has explicitly dismissed them too many times.
 const base::Feature kBlockPromptsIfDismissedOften{
diff --git a/chrome/common/chrome_features.h b/chrome/common/chrome_features.h
index 3e6348d..1ac4866 100644
--- a/chrome/common/chrome_features.h
+++ b/chrome/common/chrome_features.h
@@ -46,8 +46,6 @@
 extern const base::Feature kBackgroundModeAllowRestart;
 #endif  // defined(OS_WIN) || defined(OS_LINUX)
 
-extern const base::Feature kBackspaceGoesBackFeature;
-
 extern const base::Feature kBlockPromptsIfDismissedOften;
 extern const base::Feature kBlockPromptsIfIgnoredOften;