Remove SwipingFromLeftEdgeToGoBack flag.

Bug: 1111005
Change-Id: I29a8281cea3dc067904f708fe5049d3fd55766bf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2330034
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793248}

ash/public/cpp/ash_features.cc

@@ -106,9 +106,6 @@ const base::Feature kSwapSideVolumeButtonsForOrientation{
 const base::Feature kEnableBackgroundBlur{"EnableBackgroundBlur",
                                           base::FEATURE_ENABLED_BY_DEFAULT};
 
-const base::Feature kSwipingFromLeftEdgeToGoBack{
-    "SwipingFromLeftEdgeToGoBack", base::FEATURE_ENABLED_BY_DEFAULT};
-
 const base::Feature kDragFromShelfToHomeOrOverview{
     "DragFromShelfToHomeOrOverview", base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -220,10 +217,6 @@ bool IsBackgroundBlurEnabled() {
 #endif
 }
 
-bool IsSwipingFromLeftEdgeToGoBackEnabled() {
-  return base::FeatureList::IsEnabled(kSwipingFromLeftEdgeToGoBack);
-}
-
 bool IsDragFromShelfToHomeOrOverviewEnabled() {
   // The kDragFromShelfToHomeOrOverview feature is only enabled on the devices
   // that have hotseat enabled (i.e., on Krane and on Dogfood devices) in M80.

ash/public/cpp/ash_features.h

@@ -135,10 +135,6 @@ ASH_PUBLIC_EXPORT extern const base::Feature kShelfAppScaling;
 // may have choppier app list animations while in this mode. crbug.com/765292.
 ASH_PUBLIC_EXPORT extern const base::Feature kEnableBackgroundBlur;
 
-// Enables going back to previous page while swiping from the left edge of the
-// display. Only for tablet mode.
-ASH_PUBLIC_EXPORT extern const base::Feature kSwipingFromLeftEdgeToGoBack;
-
 // Enables dragging from shelf to enter home screen or overview feature.
 // Only for tablet mode.
 // TODO(https://crbug.com/992642): Remove this after this feature is fully
@@ -210,8 +206,6 @@ ASH_PUBLIC_EXPORT bool IsSwapSideVolumeButtonsForOrientationEnabled();
 
 ASH_PUBLIC_EXPORT bool IsBackgroundBlurEnabled();
 
-ASH_PUBLIC_EXPORT bool IsSwipingFromLeftEdgeToGoBackEnabled();
-
 ASH_PUBLIC_EXPORT bool IsDragFromShelfToHomeOrOverviewEnabled();
 
 ASH_PUBLIC_EXPORT bool IsReduceDisplayNotificationsEnabled();

ash/shell.cc

@@ -1023,10 +1023,8 @@ void Shell::Init(
   event_transformation_handler_.reset(new EventTransformationHandler);
   AddPreTargetHandler(event_transformation_handler_.get());
 
-  if (features::IsSwipingFromLeftEdgeToGoBackEnabled()) {
-    back_gesture_event_handler_ = std::make_unique<BackGestureEventHandler>();
-    AddPreTargetHandler(back_gesture_event_handler_.get());
-  }
+  back_gesture_event_handler_ = std::make_unique<BackGestureEventHandler>();
+  AddPreTargetHandler(back_gesture_event_handler_.get());
 
   toplevel_window_event_handler_ =
       std::make_unique<ToplevelWindowEventHandler>();

ash/wm/gestures/back_gesture/back_gesture_event_handler.cc

@@ -304,7 +304,6 @@ void BackGestureEventHandler::OnGestureEvent(GestureConsumer* consumer,
 bool BackGestureEventHandler::MaybeHandleBackGesture(
     ui::GestureEvent* event,
     const gfx::Point& screen_location) {
-  DCHECK(features::IsSwipingFromLeftEdgeToGoBackEnabled());
   switch (event->type()) {
     case ui::ET_GESTURE_TAP_DOWN:
       going_back_started_ = CanStartGoingBack(screen_location);
@@ -420,8 +419,6 @@ bool BackGestureEventHandler::MaybeHandleBackGesture(
 
 bool BackGestureEventHandler::CanStartGoingBack(
     const gfx::Point& screen_location) {
-  DCHECK(features::IsSwipingFromLeftEdgeToGoBackEnabled());
-
   Shell* shell = Shell::Get();
   if (!shell->tablet_mode_controller()->InTabletMode())
     return false;

ash/wm/gestures/back_gesture/back_gesture_event_handler_unittest.cc

@@ -13,7 +13,6 @@
 #include "ash/home_screen/home_screen_controller.h"
 #include "ash/keyboard/ui/keyboard_ui_controller.h"
 #include "ash/keyboard/ui/test/keyboard_test_util.h"
-#include "ash/public/cpp/ash_features.h"
 #include "ash/public/cpp/keyboard/keyboard_controller.h"
 #include "ash/screen_util.h"
 #include "ash/session/session_controller_impl.h"
@@ -33,7 +32,6 @@
 #include "ash/wm/workspace/backdrop_controller.h"
 #include "ash/wm/workspace/workspace_layout_manager.h"
 #include "ash/wm/workspace_controller.h"
-#include "base/test/scoped_feature_list.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/accelerators/test_accelerator_target.h"
@@ -62,7 +60,6 @@ class BackGestureEventHandlerTest : public AshTestBase {
     }
     AshTestBase::SetUp(std::move(delegate));
 
-    feature_list_.InitAndEnableFeature(features::kSwipingFromLeftEdgeToGoBack);
     RecreateTopWindow(AppType::BROWSER);
     TabletModeControllerTestApi().EnterTabletMode();
   }
@@ -119,7 +116,6 @@ class BackGestureEventHandlerTest : public AshTestBase {
 
  private:
   bool can_go_back_;
-  base::test::ScopedFeatureList feature_list_;
   std::unique_ptr<aura::Window> top_window_;
 };
 

ash/wm/window_util.cc

@@ -356,9 +356,6 @@ aura::Window* GetTopWindow() {
 }
 
 bool ShouldMinimizeTopWindowOnBack() {
-  if (!features::IsSwipingFromLeftEdgeToGoBackEnabled())
-    return false;
-
   Shell* shell = Shell::Get();
   if (!shell->tablet_mode_controller()->InTabletMode())
     return false;

chrome/browser/about_flags.cc

@@ -4873,11 +4873,6 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kAppServiceIntentHandlingDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(features::kAppServiceIntentHandling)},
 
-    {"ash-swiping-from-left-edge-to-go-back",
-     flag_descriptions::kAshSwipingFromLeftEdgeToGoBackName,
-     flag_descriptions::kAshSwipingFromLeftEdgeToGoBackDescription, kOsCrOS,
-     FEATURE_VALUE_TYPE(ash::features::kSwipingFromLeftEdgeToGoBack)},
-
     {"use-fake-device-for-media-stream",
      flag_descriptions::kUseFakeDeviceForMediaStreamName,
      flag_descriptions::kUseFakeDeviceForMediaStreamDescription, kOsCrOS,