ash: Clean up classic-view tablet tab dragging feature - part 4

In this CL:
- TabletModeBrowserWindowDragSessionWindowsHider is moved from
  ash/wm/tablet_mode to ash/drag_drop and renamed to
  TabDragDropWindowsHider since it's now only used by the webui tab drag
  code.
- Clean up the unused parameter of DropTargetView
- Remove the unused vector icon

Bug: b/270442617
Change-Id: Idf0a0607aadca17ba749eab78c6d4e86f5f70783
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4288655
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1118857}

ash/BUILD.gn

@@ -527,6 +527,8 @@ component("ash") {
     "drag_drop/scoped_drag_drop_observer.h",
     "drag_drop/tab_drag_drop_delegate.cc",
     "drag_drop/tab_drag_drop_delegate.h",
+    "drag_drop/tab_drag_drop_windows_hider.cc",
+    "drag_drop/tab_drag_drop_windows_hider.h",
     "drag_drop/toplevel_window_drag_delegate.h",
     "events/accessibility_event_rewriter.cc",
     "events/accessibility_event_rewriter.h",
@@ -2287,8 +2289,6 @@ component("ash") {
     "wm/overview/delayed_animation_observer.h",
     "wm/overview/delayed_animation_observer_impl.cc",
     "wm/overview/delayed_animation_observer_impl.h",
-    "wm/overview/drop_target_view.cc",
-    "wm/overview/drop_target_view.h",
     "wm/overview/overview_animation_state_waiter.cc",
     "wm/overview/overview_animation_state_waiter.h",
     "wm/overview/overview_constants.h",
@@ -2390,8 +2390,6 @@ component("ash") {
     "wm/tablet_mode/internal_input_devices_event_blocker.h",
     "wm/tablet_mode/scoped_skip_user_session_blocked_check.cc",
     "wm/tablet_mode/scoped_skip_user_session_blocked_check.h",
-    "wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.cc",
-    "wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.h",
     "wm/tablet_mode/tablet_mode_controller.cc",
     "wm/tablet_mode/tablet_mode_controller.h",
     "wm/tablet_mode/tablet_mode_multitask_cue.cc",
@@ -2945,6 +2943,7 @@ test("ash_unittests") {
     "drag_drop/drag_drop_unittest.cc",
     "drag_drop/drag_image_view_unittest.cc",
     "drag_drop/tab_drag_drop_delegate_unittest.cc",
+    "drag_drop/tab_drag_drop_windows_hider_unittest.cc",
     "events/accessibility_event_rewriter_unittest.cc",
     "events/keyboard_capability_unittest.cc",
     "events/keyboard_driven_event_rewriter_unittest.cc",
@@ -3419,7 +3418,6 @@ test("ash_unittests") {
     "wm/system_gesture_event_filter_unittest.cc",
     "wm/system_modal_container_layout_manager_unittest.cc",
     "wm/tablet_mode/accelerometer_test_data_literals.cc",
-    "wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider_unittest.cc",
     "wm/tablet_mode/tablet_mode_controller_unittest.cc",
     "wm/tablet_mode/tablet_mode_multitask_cue_unittest.cc",
     "wm/tablet_mode/tablet_mode_multitask_menu_event_handler_unittest.cc",

ash/drag_drop/tab_drag_drop_delegate.cc

@@ -6,6 +6,7 @@
 
 #include "ash/constants/app_types.h"
 #include "ash/constants/ash_features.h"
+#include "ash/drag_drop/tab_drag_drop_windows_hider.h"
 #include "ash/public/cpp/new_window_delegate.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ash/screen_util.h"
@@ -17,7 +18,6 @@
 #include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/splitview/split_view_drag_indicators.h"
 #include "ash/wm/splitview/split_view_utils.h"
-#include "ash/wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.h"
 #include "ash/wm/wm_metrics.h"
 #include "base/pickle.h"
 #include "base/strings/utf_string_conversions.h"
@@ -300,9 +300,7 @@ void TabDragDropDelegate::UpdateSourceWindowBoundsIfNecessary(
     return;
 
   if (!windows_hider_) {
-    windows_hider_ =
-        std::make_unique<TabletModeBrowserWindowDragSessionWindowsHider>(
-            source_window_, nullptr);
+    windows_hider_ = std::make_unique<TabDragDropWindowsHider>(source_window_);
   }
 
   gfx::Rect new_source_window_bounds;

ash/drag_drop/tab_drag_drop_delegate.h

@@ -9,6 +9,7 @@
 
 #include "ash/ash_export.h"
 #include "ash/drag_drop/drag_drop_capture_delegate.h"
+#include "ash/drag_drop/tab_drag_drop_windows_hider.h"
 #include "ash/wm/splitview/split_view_controller.h"
 #include "ui/aura/window_observer.h"
 #include "ui/gfx/geometry/point.h"
@@ -20,12 +21,12 @@ class Window;
 namespace ui {
 class OSExchangeData;
 class PresentationTimeRecorder;
-}
+}  // namespace ui
 
 namespace ash {
 
 class SplitViewDragIndicators;
-class TabletModeBrowserWindowDragSessionWindowsHider;
+class TabDragDropWindowsHider;
 
 // Provides special handling for Chrome tab drags on behalf of
 // DragDropController. This must be created at the beginning of a tab drag and
@@ -105,8 +106,7 @@ class ASH_EXPORT TabDragDropDelegate : public DragDropCaptureDelegate,
   const gfx::Point start_location_in_screen_;
 
   std::unique_ptr<SplitViewDragIndicators> split_view_drag_indicators_;
-  std::unique_ptr<TabletModeBrowserWindowDragSessionWindowsHider>
-      windows_hider_;
+  std::unique_ptr<TabDragDropWindowsHider> windows_hider_;
 
   // Presentation time recorder for tab dragging in tablet mode with webui
   // tab strip enable.

ash/wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.cc → ash/drag_drop/tab_drag_drop_windows_hider.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.h"
+#include "ash/drag_drop/tab_drag_drop_windows_hider.h"
 
 #include <vector>
 
@@ -21,15 +21,9 @@
 
 namespace ash {
 
-TabletModeBrowserWindowDragSessionWindowsHider::
-    TabletModeBrowserWindowDragSessionWindowsHider(aura::Window* source_window,
-                                                   aura::Window* dragged_window)
-    : source_window_(source_window), dragged_window_(dragged_window) {
+TabDragDropWindowsHider::TabDragDropWindowsHider(aura::Window* source_window)
+    : source_window_(source_window) {
   DCHECK(source_window_);
-  if (dragged_window_) {
-    DCHECK_EQ(source_window_,
-              dragged_window_->GetProperty(kTabDraggingSourceWindowKey));
-  }
 
   root_window_ = source_window_->GetRootWindow();
 
@@ -41,8 +35,7 @@ TabletModeBrowserWindowDragSessionWindowsHider::
   std::vector<aura::Window*> windows =
       Shell::Get()->mru_window_tracker()->BuildMruWindowList(kActiveDesk);
   for (aura::Window* window : windows) {
-    if (window == dragged_window_ || window == source_window_ ||
-        window->GetRootWindow() != root_window_) {
+    if (window == source_window_ || window->GetRootWindow() != root_window_) {
       continue;
     }
 
@@ -63,11 +56,11 @@ TabletModeBrowserWindowDragSessionWindowsHider::
       ->SetWallpaperBlur(wallpaper_constants::kOverviewBlur);
 }
 
-TabletModeBrowserWindowDragSessionWindowsHider::
-    ~TabletModeBrowserWindowDragSessionWindowsHider() {
+TabDragDropWindowsHider::~TabDragDropWindowsHider() {
   // It might be possible that |source_window_| is destroyed during dragging.
-  if (source_window_)
+  if (source_window_) {
     WindowBackdrop::Get(source_window_)->RestoreBackdrop();
+  }
 
   for (auto iter = window_visibility_map_.begin();
        iter != window_visibility_map_.end(); ++iter) {
@@ -90,8 +83,7 @@ TabletModeBrowserWindowDragSessionWindowsHider::
       ->SetWallpaperBlur(wallpaper_constants::kClear);
 }
 
-void TabletModeBrowserWindowDragSessionWindowsHider::OnWindowDestroying(
-    aura::Window* window) {
+void TabDragDropWindowsHider::OnWindowDestroying(aura::Window* window) {
   if (window == source_window_) {
     source_window_ = nullptr;
     return;
@@ -100,13 +92,13 @@ void TabletModeBrowserWindowDragSessionWindowsHider::OnWindowDestroying(
   window->RemoveObserver(this);
   window_visibility_map_.erase(window);
 }
-void TabletModeBrowserWindowDragSessionWindowsHider::OnWindowVisibilityChanged(
-    aura::Window* window,
-    bool visible) {
+void TabDragDropWindowsHider::OnWindowVisibilityChanged(aura::Window* window,
+                                                        bool visible) {
   // The window object is not necessarily the one that is being observed.
   // So we only take action if the window is currently being observed.
-  if (window_visibility_map_.count(window) == 0)
+  if (window_visibility_map_.count(window) == 0) {
     return;
+  }
 
   if (visible) {
     // Do not let |window| change to visible during the lifetime of |this|.
@@ -119,8 +111,7 @@ void TabletModeBrowserWindowDragSessionWindowsHider::OnWindowVisibilityChanged(
   // ignored.
 }
 
-int TabletModeBrowserWindowDragSessionWindowsHider::
-    GetWindowVisibilityMapSizeForTesting() const {
+int TabDragDropWindowsHider::GetWindowVisibilityMapSizeForTesting() const {
   return window_visibility_map_.size();
 }
 

ash/drag_drop/tab_drag_drop_windows_hider.h

@@ -0,0 +1,52 @@
+// Copyright 2020 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_DRAG_DROP_TAB_DRAG_DROP_WINDOWS_HIDER_H_
+#define ASH_DRAG_DROP_TAB_DRAG_DROP_WINDOWS_HIDER_H_
+
+#include <map>
+
+#include "ash/ash_export.h"
+#include "ui/aura/window.h"
+#include "ui/aura/window_observer.h"
+
+namespace ash {
+
+// Hides all visible windows except the source window from which the webui tab
+// drag originates, and restores the windows' visibility upon its destruction.
+// It also blurs and darkens the background, hides the home launcher if home
+// launcher is enabled. Only need to do so if we need to scale up and down the
+// source window when dragging a web ui tab out of it.
+class ASH_EXPORT TabDragDropWindowsHider : public aura::WindowObserver {
+ public:
+  explicit TabDragDropWindowsHider(aura::Window* source_window);
+
+  TabDragDropWindowsHider(const TabDragDropWindowsHider&) = delete;
+  TabDragDropWindowsHider& operator=(const TabDragDropWindowsHider&) = delete;
+
+  ~TabDragDropWindowsHider() override;
+
+  // aura::WindowObserver:
+  void OnWindowDestroying(aura::Window* window) override;
+  void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
+
+  int GetWindowVisibilityMapSizeForTesting() const;
+
+ private:
+  // The window from which the drag originated.
+  aura::Window* source_window_;
+
+  // The root window the drag is taking place within. Guaranteed to be
+  // non-null during the lifetime of |this|.
+  aura::Window* root_window_;
+
+  // Maintains the map between windows and their visibilities. All windows
+  // except the dragged window and the source window should stay hidden during
+  // dragging.
+  std::map<aura::Window*, bool> window_visibility_map_;
+};
+
+}  // namespace ash
+
+#endif  // ASH_DRAG_DROP_TAB_DRAG_DROP_WINDOWS_HIDER_H_

ash/wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider_unittest.cc → ash/drag_drop/tab_drag_drop_windows_hider_unittest.cc

@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/wm/tablet_mode/tablet_mode_browser_window_drag_session_windows_hider.h"
+#include "ash/drag_drop/tab_drag_drop_windows_hider.h"
 
 #include "ash/test/ash_test_base.h"
 
 namespace ash {
 
-class TabletModeBrowserWindowDragSessionWindowsHiderTest : public AshTestBase {
+class TabDragDropWindowsHiderTest : public AshTestBase {
  public:
   // AshTestBase:
   void SetUp() override {
@@ -26,16 +26,14 @@ class TabletModeBrowserWindowDragSessionWindowsHiderTest : public AshTestBase {
 };
 
 // Test for crbug.com/1330038 .
-TEST_F(TabletModeBrowserWindowDragSessionWindowsHiderTest,
-       WindowVisibilityChangedDuringDrag) {
+TEST_F(TabDragDropWindowsHiderTest, WindowVisibilityChangedDuringDrag) {
   std::unique_ptr<aura::Window> source_window = CreateToplevelTestWindow();
 
   // Create a sub window and hide it.
   std::unique_ptr<aura::Window> sub_window = CreateTestWindow();
   dummy_window_->AddChild(sub_window.get());
   sub_window->Hide();
-  auto hider = std::make_unique<TabletModeBrowserWindowDragSessionWindowsHider>(
-      source_window.get(), nullptr);
+  auto hider = std::make_unique<TabDragDropWindowsHider>(source_window.get());
   int size = hider->GetWindowVisibilityMapSizeForTesting();
 
   // Show the sub window. Make sure the window observer list size remains the

ash/resources/vector_icons/BUILD.gn

@@ -222,7 +222,6 @@ aggregate_vector_icons("ash_vector_icons") {
     "notification_timer.icon",
     "overflow_shelf_left.icon",
     "overflow_shelf_right.icon",
-    "overview_drop_target_plus.icon",
     "overview_window_close.icon",
     "paint_brush.icon",
     "palette_action_create_note.icon",