Turn on the reverse scrolling gesture feature.

This CL enable the feature of reverse scrolling gestures.

 - Enable reverse scrolling gesture feature.
 - Get rid of the notification for overview gestures.
 - Add toast for the gestures entering overview when the natural
 scrolling is OFF.

Bug: 1107183
Change-Id: Ibbabca1b5deb5b37c8b697ff732f5312519e3adc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510350Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Xiaodan Zhu <zxdan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824219}

ash/ash_prefs.cc

@@ -37,7 +37,6 @@
 #include "ash/touch/touch_devices_controller.h"
 #include "ash/wallpaper/wallpaper_controller_impl.h"
 #include "ash/wm/desks/desks_restore_util.h"
-#include "ash/wm/gestures/wm_gesture_handler.h"
 #include "chromeos/components/quick_answers/public/cpp/quick_answers_prefs.h"
 #include "chromeos/constants/chromeos_pref_names.h"
 #include "chromeos/services/assistant/public/cpp/assistant_prefs.h"
@@ -75,7 +74,6 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry, bool for_test) {
   ShelfController::RegisterProfilePrefs(registry);
   TouchDevicesController::RegisterProfilePrefs(registry, for_test);
   tray::VPNListView::RegisterProfilePrefs(registry);
-  WmGestureHandler::RegisterProfilePrefs(registry);
   MediaTray::RegisterProfilePrefs(registry);
 
   // Provide prefs registered in the browser for ash_unittests.

ash/ash_strings.grd

@@ -520,11 +520,11 @@ This file contains the strings for ash.
       <message name="IDS_GESTURE_NOTIFICATION_MESSAGE_LEARN_MORE" desc="The body of the notification to show off new gestures. This notification body links to the help page for the gestures.">
         Use gestures to quickly switch between apps and interact with your Chromebook in tablet mode.
       </message>
-      <message name="IDS_OVERVIEW_REVERSE_GESTURE_NOTIFICATION_TITLE" desc="The title of the notification to change reverse gesture when entering/exiting overview mode">
-        The Overview touchpad gesture has changed
+      <message name="IDS_CHANGE_ENTER_OVERVIEW_REVERSE_GESTURE" desc="The toast of changing enter overview gesture">
+        The touchpad gesture to enter Overview has changed. Swipe up with three fingers to enter Overview.
       </message>
-      <message name="IDS_OVERVIEW_REVERSE_GESTURE_NOTIFICATION_MESSAGE" desc="The body of the notification to change reverse gesture when entering/exiting overview mode">
-        Swipe up with three fingers to open and down to close the Overview.
+      <message name="IDS_CHANGE_EXIT_OVERVIEW_REVERSE_GESTURE" desc="The toast of changing exit overview gesture">
+        The touchpad gesture to exit Overview has changed. Swipe down with three fingers to exit Overview.
       </message>
       <message name="IDS_CHANGE_NEXT_DESK_REVERSE_GESTURE" desc="The toast of changing reverse gesture to switch to the next desk.">
         The touchpad gesture to switch to the next desk has changed. Swipe right with four fingers to switch to the next desk.

ash/ash_strings_grd/IDS_CHANGE_ENTER_OVERVIEW_REVERSE_GESTURE.png.sha1

+33e60d7fae900329ccf2d68cfd7a84138a10b515
\ No newline at end of file

ash/ash_strings_grd/IDS_CHANGE_EXIT_OVERVIEW_REVERSE_GESTURE.png.sha1

+89bcdf911a81ba210c539d5ad983c6b8208ff9a9
\ No newline at end of file

ash/ash_strings_grd/IDS_OVERVIEW_REVERSE_GESTURE_NOTIFICATION_MESSAGE.png.sha1

-20bc6189a45f4cd148cfa3bae5f41ed4b9223588
\ No newline at end of file

ash/ash_strings_grd/IDS_OVERVIEW_REVERSE_GESTURE_NOTIFICATION_TITLE.png.sha1

-20bc6189a45f4cd148cfa3bae5f41ed4b9223588
\ No newline at end of file

ash/public/cpp/ash_features.cc

@@ -118,7 +118,7 @@ const base::Feature kHideShelfControlsInTabletMode{
     "HideShelfControlsInTabletMode", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kReverseScrollGestures{"EnableReverseScrollGestures",
-                                           base::FEATURE_DISABLED_BY_DEFAULT};
+                                           base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kSystemTrayMicGainSetting{"SystemTrayMicGainSetting",
                                               base::FEATURE_ENABLED_BY_DEFAULT};

ash/public/cpp/ash_pref_names.cc

@@ -579,11 +579,6 @@ const char kColorModeThemed[] = "cros.system.color_mode_themed";
 const char kAppNotificationBadgingEnabled[] =
     "ash.app_notification_badging_enabled";
 
-// An integer pref that counts how many times the reverse gesture notification
-// shows.
-const char kReverseGestureNotificationCount[] =
-    "ash.wm.reverse_gesture_notification_count";
-
 // An integer pref that indicates whether global media controls is pinned to
 // shelf or it's unset and need to be determined by screen size during runtime.
 const char kGlobalMediaControlsPinned[] =

ash/public/cpp/ash_pref_names.h

@@ -209,8 +209,6 @@ ASH_PUBLIC_EXPORT extern const char kColorModeThemed[];
 
 ASH_PUBLIC_EXPORT extern const char kAppNotificationBadgingEnabled[];
 
-ASH_PUBLIC_EXPORT extern const char kReverseGestureNotificationCount[];
-
 ASH_PUBLIC_EXPORT extern const char kGlobalMediaControlsPinned[];
 
 }  // namespace prefs

ash/wm/gestures/wm_gesture_handler.h

@@ -55,8 +55,6 @@ class ASH_EXPORT WmGestureHandler {
   // otherwise.
   bool ProcessScrollEvent(const ui::ScrollEvent& event);
 
-  static void RegisterProfilePrefs(PrefRegistrySimple* registry);
-
  private:
   // A struct containing the relevant data during a scroll session.
   struct ScrollData {

ash/wm/gestures/wm_gesture_handler_unittest.cc

@@ -33,9 +33,6 @@ constexpr int kNumFingersForWindowCycle = 2;
 constexpr int kNumFingersForHighlight = 3;
 constexpr int kNumFingersForDesksSwitch = 4;
 
-constexpr char kOverviewGestureNotificationId[] =
-    "ash.wm.reverse_overview_gesture";
-
 bool InOverviewSession() {
   return Shell::Get()->overview_controller()->InOverviewSession();
 }
@@ -51,18 +48,6 @@ bool IsNaturalScrollOn() {
          pref->GetBoolean(prefs::kNaturalScroll);
 }
 
-bool IsOverviewReverseGestureNotificationShown() {
-  return message_center::MessageCenter::Get()->FindVisibleNotificationById(
-      kOverviewGestureNotificationId);
-}
-
-void CloseOverviewReverseGestureNotification() {
-  if (IsOverviewReverseGestureNotificationShown()) {
-    message_center::MessageCenter::Get()->RemoveNotification(
-        kOverviewGestureNotificationId, true);
-  }
-}
-
 int GetOffsetX(int offset) {
   // The handler code uses the new directions which is the reverse of the old
   // handler code. Reverse the offset if the ReverseScrollGestures feature is
@@ -141,32 +126,17 @@ TEST_F(WmGestureHandlerTest, WrongVerticalScrolls) {
 
   const float long_scroll = 2 * WmGestureHandler::kVerticalThresholdDp;
 
-  // Swiping down can enter overview but a notification will be shown.
+  // Swiping down cannot enter overview.
   Scroll(0, -long_scroll, 3);
-  EXPECT_TRUE(InOverviewSession());
-  // Notification is shown for the first time.
-  EXPECT_TRUE(IsOverviewReverseGestureNotificationShown());
-  CloseOverviewReverseGestureNotification();
-
-  // Swiping up can exit overview, but a notification will be shown.
-  Scroll(0, long_scroll, 3);
   EXPECT_FALSE(InOverviewSession());
-  // Notification is shown for the second time.
-  EXPECT_TRUE(IsOverviewReverseGestureNotificationShown());
-  CloseOverviewReverseGestureNotification();
 
-  // Swiping down triggers the notification for the last time.
-  Scroll(0, -long_scroll, 3);
+  // Enter overview.
+  Scroll(0, long_scroll, 3);
   EXPECT_TRUE(InOverviewSession());
-  // Notification is shown for the third (last) time.
-  EXPECT_TRUE(IsOverviewReverseGestureNotificationShown());
-  CloseOverviewReverseGestureNotification();
 
-  // Doing wrong gesture again won't trigger notification anymore.
+  // Swiping up cannot exit overview.
   Scroll(0, long_scroll, 3);
-  EXPECT_FALSE(InOverviewSession());
-  // No notification will be shown anymore.
-  EXPECT_FALSE(IsOverviewReverseGestureNotificationShown());
+  EXPECT_TRUE(InOverviewSession());
 }
 
 // Tests three or four finger horizontal scroll gesture (depending on flags) to