Remove HomeLauncherGestureHandler

With recent changes HomeLauncherGestureHandler has become a wrapper
around a SwipeHomeToOverviewController used by ShelfLayoutManager.
This CL adds SwipeHomeToOverviewController to ShelfLayoutManager, and
removes the unnecessary level of abstraction.

BUG=1137452

Change-Id: I19974b96a57718186137ba663dc2fc6b53ee90ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532971
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827308}

ash/BUILD.gn

@@ -475,8 +475,6 @@ component("ash") {
     "highlighter/highlighter_view.h",
     "home_screen/drag_window_from_shelf_controller.cc",
     "home_screen/drag_window_from_shelf_controller.h",
-    "home_screen/home_launcher_gesture_handler.cc",
-    "home_screen/home_launcher_gesture_handler.h",
     "home_screen/home_screen_controller.cc",
     "home_screen/home_screen_controller.h",
     "home_screen/home_screen_delegate.h",

ash/app_list/app_list_controller_impl.cc

@@ -22,7 +22,6 @@
 #include "ash/assistant/ui/assistant_view_delegate.h"
 #include "ash/assistant/util/assistant_util.h"
 #include "ash/assistant/util/deep_link_util.h"
-#include "ash/home_screen/home_launcher_gesture_handler.h"
 #include "ash/home_screen/home_screen_controller.h"
 #include "ash/keyboard/ui/keyboard_ui_controller.h"
 #include "ash/public/cpp/app_list/app_list_client.h"

ash/app_list/app_list_controller_impl_unittest.cc

@@ -18,7 +18,6 @@
 #include "ash/app_list/views/expand_arrow_view.h"
 #include "ash/app_list/views/search_box_view.h"
 #include "ash/app_list/views/test/apps_grid_view_test_api.h"
-#include "ash/home_screen/home_launcher_gesture_handler.h"
 #include "ash/home_screen/home_screen_controller.h"
 #include "ash/ime/ime_controller_impl.h"
 #include "ash/ime/test_ime_controller_client.h"

ash/app_list/views/contents_view.cc

@@ -168,7 +168,7 @@ void ContentsView::ResetForShow() {
   SetActiveState(AppListState::kStateApps, /*animate=*/false);
   // In side shelf, the opacity of the contents is not animated so set it to the
   // final state. In tablet mode, opacity of the elements is controlled by the
-  // HomeLauncherGestureHandler which expects these elements to be opaque.
+  // HomeScreenController which expects these elements to be opaque.
   // Otherwise the contents animate from 0 to 1 so set the initial opacity to 0.
   if (app_list_view_->is_side_shelf() || app_list_view_->is_tablet_mode()) {
     AnimateToViewState(AppListViewState::kFullscreenAllApps, base::TimeDelta());

ash/home_screen/home_screen_controller.cc

@@ -8,7 +8,6 @@
 #include <vector>
 
 #include "ash/app_list/app_list_controller_impl.h"
-#include "ash/home_screen/home_launcher_gesture_handler.h"
 #include "ash/home_screen/home_screen_delegate.h"
 #include "ash/home_screen/window_scale_animation.h"
 #include "ash/public/cpp/ash_features.h"
@@ -105,9 +104,7 @@ class WindowAnimationsCallback : public ui::LayerAnimationObserver {
 
 }  // namespace
 
-HomeScreenController::HomeScreenController()
-    : home_launcher_gesture_handler_(
-          std::make_unique<HomeLauncherGestureHandler>()) {
+HomeScreenController::HomeScreenController() {
   Shell::Get()->overview_controller()->AddObserver(this);
   Shell::Get()->wallpaper_controller()->AddObserver(this);
 }

ash/home_screen/home_screen_controller.h

@@ -25,12 +25,10 @@ class ThroughputTracker;
 
 namespace ash {
 
-class HomeLauncherGestureHandler;
 class HomeScreenDelegate;
 
-// HomeScreenController handles the home launcher (e.g., tablet-mode app list)
-// and owns the HomeLauncherGestureHandler that transitions the launcher window
-// and other windows when the launcher is shown, hidden or animated.
+// HomeScreenController provides functionality to control the home launcher -
+// the tablet mode app list.
 class ASH_EXPORT HomeScreenController : public OverviewObserver,
                                         public SplitViewObserver,
                                         public WallpaperControllerObserver {
@@ -85,10 +83,6 @@ class ASH_EXPORT HomeScreenController : public OverviewObserver,
 
   HomeScreenDelegate* delegate() { return delegate_; }
 
-  HomeLauncherGestureHandler* home_launcher_gesture_handler() {
-    return home_launcher_gesture_handler_.get();
-  }
-
  private:
   // OverviewObserver:
   void OnOverviewModeStarting() override;
@@ -122,10 +116,6 @@ class ASH_EXPORT HomeScreenController : public OverviewObserver,
   // Not owned.
   HomeScreenDelegate* delegate_ = nullptr;
 
-  // Owned pointer to the object which handles gestures related to the home
-  // launcher.
-  std::unique_ptr<HomeLauncherGestureHandler> home_launcher_gesture_handler_;
-
   // Presenter that manages home screen animations.
   HomeScreenPresenter home_screen_presenter_{this};
 

ash/home_screen/swipe_home_to_overview_controller.h

@@ -16,7 +16,7 @@
 
 namespace ash {
 
-// Used by HomeLauncherGestureHandler to handle gesture drag events while the
+// Used by ShelfLayoutManager to handle gesture drag events while the
 // handler is in kSwipeHomeToOverview mode. The controller handles swipe gesture
 // from hot seat on the home screen. The gesture, if detected, transitions the
 // home screen to the overview UI.

ash/shelf/home_to_overview_nudge_controller_unittest.cc

@@ -4,8 +4,6 @@
 
 #include "ash/shelf/home_to_overview_nudge_controller.h"
 
-#include "ash/home_screen/home_launcher_gesture_handler.h"
-#include "ash/home_screen/home_screen_controller.h"
 #include "ash/home_screen/swipe_home_to_overview_controller.h"
 #include "ash/public/cpp/ash_features.h"
 #include "ash/public/cpp/ash_pref_names.h"
@@ -625,9 +623,8 @@ TEST_F(HomeToOverviewNudgeControllerTest, NoNudgeAfterSuccessfulGestures) {
               // transition to overview (which happens after swipe moves far
               // enough), run it to trigger transition to overview.
               SwipeHomeToOverviewController* swipe_controller =
-                  Shell::Get()
-                      ->home_screen_controller()
-                      ->home_launcher_gesture_handler()
+                  GetPrimaryShelf()
+                      ->shelf_layout_manager()
                       ->swipe_home_to_overview_controller_for_testing();
               ASSERT_TRUE(swipe_controller);
 
@@ -678,9 +675,8 @@ TEST_F(HomeToOverviewNudgeControllerTest, HomeToOverviewGestureFromNudge) {
         // transition to overview (which happens after swipe moves far
         // enough), run it to trigger transition to overview.
         SwipeHomeToOverviewController* swipe_controller =
-            Shell::Get()
-                ->home_screen_controller()
-                ->home_launcher_gesture_handler()
+            GetPrimaryShelf()
+                ->shelf_layout_manager()
                 ->swipe_home_to_overview_controller_for_testing();
         ASSERT_TRUE(swipe_controller);
 

ash/shelf/hotseat_widget_unittest.cc

@@ -1590,8 +1590,8 @@ TEST_P(HotseatWidgetTest, HotseatFlushWithScreenBottomInClamshell) {
   EXPECT_EQ(hotseat_bottom, display_height);
 }
 
-// Tests that when hotseat and drag-window-to-overview features are both
-// enabled, HomeLauncherGestureHandler can receive and process events properly.
+// Tests that upward drag gesture from the shelf in tablet mode affects the
+// active window presentation.
 TEST_P(HotseatWidgetTest, DragActiveWindowInTabletMode) {
   GetPrimaryShelf()->SetAutoHideBehavior(shelf_auto_hide_behavior());
   TabletModeControllerTestApi().EnterTabletMode();