Remove ash::switches::kAshEnableV1AppBackButton

browser_non_client_frame_view_ash.cc includes
ash/public/cpp/ash_switches.h to make use of the
`kAshEnableV1AppBackButton` runtime switch. However, as
for the bug linked to its declaration, the support is
flagged for removal (https://crbug.com/749713 - WONTFIX'ed).

This CL removes it, and the code associated with it, including
if-blocks it was being checked and unittests.

This is phase 2.3 in the design document [1].

[1] https://docs.google.com/document/d/1xHwcHrAiEaWuA4usGEqKZ9zm1H8SGk3WkS-Jf2Q_los

The idea is to move browser_non_client_frame_view_ash.cc|h away from
using "ash" symbols. Ultimately, this file will be used by lacros/chrome
builds.

BUG=749713, 1113900

Change-Id: Iab1a7766f0142e66abda34a265d1308b341b2328
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424637Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Antonio Gomes (GMT-4) <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#810219}

ash/public/cpp/ash_switches.cc

@@ -43,10 +43,6 @@ const char kAshDeveloperShortcuts[] = "ash-dev-shortcuts";
 const char kAshDisableTouchExplorationMode[] =
     "ash-disable-touch-exploration-mode";
 
-// Enables Backbutton on frame for v1 apps.
-// TODO(oshima): Remove this once the feature is launched. crbug.com/749713.
-const char kAshEnableV1AppBackButton[] = "ash-enable-v1-app-back-button";
-
 // Enable cursor motion blur.
 const char kAshEnableCursorMotionBlur[] = "ash-enable-cursor-motion-blur";
 

ash/public/cpp/ash_switches.h

@@ -25,7 +25,6 @@ ASH_PUBLIC_EXPORT extern const char kAshDebugShortcuts[];
 ASH_PUBLIC_EXPORT extern const char kAshDeveloperShortcuts[];
 ASH_PUBLIC_EXPORT extern const char kAshDisableTouchExplorationMode[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableCursorMotionBlur[];
-ASH_PUBLIC_EXPORT extern const char kAshEnableV1AppBackButton[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableMagnifierKeyScroller[];
 ASH_PUBLIC_EXPORT extern const char kAshEnablePaletteOnAllDisplays[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableTabletMode[];

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.cc

@@ -8,8 +8,6 @@
 
 #include "ash/public/cpp/app_types.h"
 #include "ash/public/cpp/ash_constants.h"
-#include "ash/public/cpp/ash_switches.h"
-#include "ash/public/cpp/caption_buttons/frame_back_button.h"
 #include "ash/public/cpp/caption_buttons/frame_caption_button_container_view.h"
 #include "ash/public/cpp/default_frame_header.h"
 #include "ash/public/cpp/frame_utils.h"
@@ -17,18 +15,15 @@
 #include "ash/public/cpp/window_properties.h"
 #include "ash/public/cpp/window_state_type.h"
 #include "ash/wm/window_util.h"
-#include "base/command_line.h"
 #include "base/metrics/user_metrics.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
-#include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/profiles/profiles_state.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager_helper.h"
 #include "chrome/browser/ui/ash/session_util.h"
 #include "chrome/browser/ui/browser.h"
-#include "chrome/browser/ui/browser_command_controller.h"
 #include "chrome/browser/ui/layout_constants.h"
 #include "chrome/browser/ui/ui_features.h"
 #include "chrome/browser/ui/views/frame/browser_frame.h"
@@ -77,11 +72,6 @@ constexpr SkColor kIncognitoWindowTitleTextColor = SK_ColorWHITE;
 // The indicator for teleported windows has 8 DIPs before and below it.
 constexpr int kProfileIndicatorPadding = 8;
 
-bool IsV1AppBackButtonEnabled() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      ash::switches::kAshEnableV1AppBackButton);
-}
-
 // Returns true if the header should be painted so that it looks the same as
 // the header used for packaged apps.
 bool UsePackagedAppHeaderStyle(const Browser* browser) {
@@ -104,12 +94,6 @@ BrowserNonClientFrameViewAsh::BrowserNonClientFrameViewAsh(
 }
 
 BrowserNonClientFrameViewAsh::~BrowserNonClientFrameViewAsh() {
-  if (browser_view()->browser()->deprecated_is_app() &&
-      IsV1AppBackButtonEnabled()) {
-    browser_view()->browser()->command_controller()->RemoveCommandObserver(
-        IDC_BACK, this);
-  }
-
   ash::TabletMode::Get()->RemoveObserver(this);
 
   ImmersiveModeController* immersive_controller =
@@ -150,13 +134,6 @@ void BrowserNonClientFrameViewAsh::Init() {
 
   ash::TabletMode::Get()->AddObserver(this);
 
-  if (browser->deprecated_is_app() && IsV1AppBackButtonEnabled()) {
-    browser->command_controller()->AddCommandObserver(IDC_BACK, this);
-    back_button_ = new ash::FrameBackButton();
-    AddChildView(back_button_);
-    // TODO(oshima): Add Tooltip, accessibility name.
-  }
-
   if (frame()->ShouldDrawFrameHeader())
     frame_header_ = CreateFrameHeader();
 
@@ -503,15 +480,6 @@ gfx::ImageSkia BrowserNonClientFrameViewAsh::GetFaviconForTabIconView() {
   return delegate ? delegate->GetWindowIcon() : gfx::ImageSkia();
 }
 
-void BrowserNonClientFrameViewAsh::EnabledStateChangedForCommand(int id,
-                                                                 bool enabled) {
-  DCHECK_EQ(IDC_BACK, id);
-  DCHECK(browser_view()->browser()->deprecated_is_app());
-
-  if (back_button_)
-    back_button_->SetEnabled(enabled);
-}
-
 void BrowserNonClientFrameViewAsh::OnWindowDestroying(aura::Window* window) {
   window_observer_.RemoveAll();
 }
@@ -552,8 +520,6 @@ void BrowserNonClientFrameViewAsh::OnImmersiveRevealStarted() {
   container->AddChildViewAt(caption_button_container_, 0);
   if (web_app_frame_toolbar())
     container->AddChildViewAt(web_app_frame_toolbar(), 0);
-  if (back_button_)
-    container->AddChildViewAt(back_button_, 0);
 
   container->Layout();
 }
@@ -562,8 +528,6 @@ void BrowserNonClientFrameViewAsh::OnImmersiveRevealEnded() {
   AddChildViewAt(caption_button_container_, 0);
   if (web_app_frame_toolbar())
     AddChildViewAt(web_app_frame_toolbar(), 0);
-  if (back_button_)
-    AddChildViewAt(back_button_, 0);
   Layout();
 }
 
@@ -660,7 +624,6 @@ BrowserNonClientFrameViewAsh::CreateFrameHeader() {
         frame(), this, caption_button_container_);
   }
 
-  header->SetBackButton(back_button_);
   header->SetLeftHeaderView(window_icon_);
   return header;
 }

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h

@@ -12,7 +12,6 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
-#include "chrome/browser/command_observer.h"
 #include "chrome/browser/ui/views/frame/browser_frame_header_ash.h"
 #include "chrome/browser/ui/views/frame/browser_non_client_frame_view.h"
 #include "chrome/browser/ui/views/frame/immersive_mode_controller.h"
@@ -31,17 +30,12 @@ namespace ash {
 class FrameCaptionButtonContainerView;
 }  // namespace ash
 
-namespace views {
-class FrameCaptionButton;
-}  // namespace views
-
 // Provides the BrowserNonClientFrameView for Chrome OS.
 class BrowserNonClientFrameViewAsh
     : public BrowserNonClientFrameView,
       public BrowserFrameHeaderAsh::AppearanceProvider,
       public ash::TabletModeObserver,
       public TabIconViewModel,
-      public CommandObserver,
       public aura::WindowObserver,
       public ImmersiveModeController::Observer {
  public:
@@ -97,9 +91,6 @@ class BrowserNonClientFrameViewAsh
   bool ShouldTabIconViewAnimate() const override;
   gfx::ImageSkia GetFaviconForTabIconView() override;
 
-  // CommandObserver:
-  void EnabledStateChangedForCommand(int id, bool enabled) override;
-
   // aura::WindowObserver:
   void OnWindowDestroying(aura::Window* window) override;
   void OnWindowPropertyChanged(aura::Window* window,
@@ -133,8 +124,6 @@ class BrowserNonClientFrameViewAsh
                            AppHeaderVisibilityInTabletModeTest);
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest,
                            ImmersiveModeTopViewInset);
-  FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshBackButtonTest,
-                           V1BackButton);
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest,
                            ToggleTabletModeOnMinimizedWindow);
   FRIEND_TEST_ALL_PREFIXES(WebAppNonClientFrameViewAshTest,
@@ -215,8 +204,6 @@ class BrowserNonClientFrameViewAsh
   // View which contains the window controls.
   ash::FrameCaptionButtonContainerView* caption_button_container_ = nullptr;
 
-  views::FrameCaptionButton* back_button_ = nullptr;
-
   // For popups, the window icon.
   TabIconView* window_icon_ = nullptr;
 

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash_browsertest.cc

@@ -1272,61 +1272,6 @@ IN_PROC_BROWSER_TEST_P(WebAppNonClientFrameViewAshTest, PopupHasNoToolbar) {
   EXPECT_FALSE(frame_view->web_app_frame_toolbar_for_testing());
 }
 
-namespace {
-
-class BrowserNonClientFrameViewAshBackButtonTest
-    : public TopChromeMdParamTest<InProcessBrowserTest> {
- public:
-  BrowserNonClientFrameViewAshBackButtonTest() = default;
-  ~BrowserNonClientFrameViewAshBackButtonTest() override = default;
-
-  void SetUpCommandLine(base::CommandLine* command_line) override {
-    command_line->AppendSwitch(ash::switches::kAshEnableV1AppBackButton);
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(BrowserNonClientFrameViewAshBackButtonTest);
-};
-
-}  // namespace
-
-// Test if the V1 apps' frame has a back button.
-IN_PROC_BROWSER_TEST_P(BrowserNonClientFrameViewAshBackButtonTest,
-                       V1BackButton) {
-  // Normal browser windows don't have a frame back button.
-  BrowserNonClientFrameViewAsh* frame_view =
-      GetFrameViewAsh(BrowserView::GetBrowserViewForBrowser(browser()));
-  EXPECT_FALSE(frame_view->back_button_);
-
-  browser()->window()->Close();
-
-  // Open a new app window.
-  Browser::CreateParams params = Browser::CreateParams::CreateForApp(
-      "test_browser_app", true /* trusted_source */, gfx::Rect(),
-      browser()->profile(), true);
-  params.initial_show_state = ui::SHOW_STATE_DEFAULT;
-  Browser* app_browser = new Browser(params);
-  AddBlankTabAndShow(app_browser);
-
-  BrowserNonClientFrameViewAsh* app_frame_view =
-      GetFrameViewAsh(BrowserView::GetBrowserViewForBrowser(app_browser));
-  ASSERT_TRUE(app_frame_view->back_button_);
-  EXPECT_TRUE(app_frame_view->back_button_->GetVisible());
-  // The back button should be disabled initially.
-  EXPECT_FALSE(app_frame_view->back_button_->GetEnabled());
-
-  // Nagivate to a page. The back button should now be enabled.
-  const GURL kAppStartURL("http://example.org/");
-  NavigateParams nav_params(app_browser, kAppStartURL,
-                            ui::PAGE_TRANSITION_LINK);
-  ui_test_utils::NavigateToURL(&nav_params);
-  EXPECT_TRUE(app_frame_view->back_button_->GetEnabled());
-
-  // Go back to the blank. The back button should be disabled again.
-  chrome::GoBack(app_browser, WindowOpenDisposition::CURRENT_TAB);
-  EXPECT_FALSE(app_frame_view->back_button_->GetEnabled());
-}
-
 // Test the normal type browser's kTopViewInset is always 0.
 IN_PROC_BROWSER_TEST_P(BrowserNonClientFrameViewAshTest, TopViewInset) {
   BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser());
@@ -1586,5 +1531,4 @@ INSTANTIATE_TEST_SUITE(BrowserNonClientFrameViewAshTestWithWebUiTabStrip);
 INSTANTIATE_TEST_SUITE(ImmersiveModeBrowserViewTest);
 INSTANTIATE_TEST_SUITE(ImmersiveModeBrowserViewTestNoWebUiTabStrip);
 INSTANTIATE_TEST_SUITE(WebAppNonClientFrameViewAshTest);
-INSTANTIATE_TEST_SUITE(BrowserNonClientFrameViewAshBackButtonTest);
 INSTANTIATE_TEST_SUITE(HomeLauncherBrowserNonClientFrameViewAshTest);