Cros: Fix launcher disappearing after screen rotates.

AppListControllerImpl::OnDisplayConfigurationChanged is called when the
screen rotates.

We recently refactored some visibility functions, this caused the bug.
We should check presenters visibility, not the target visibility.

Bug: 1012432
Change-Id: I2033484115de22f72fac997258c4013872e2d784
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1861154
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706229}

ash/app_list/app_list_controller_impl.cc

@@ -655,7 +655,7 @@ void AppListControllerImpl::OnDisplayConfigurationChanged() {
   // expected if it's enabled and we're still in tablet mode.
   // https://crbug.com/900956.
   const bool should_be_shown = IsTabletMode();
-  if (should_be_shown == GetTargetVisibility())
+  if (should_be_shown == presenter_.GetTargetVisibility())
     return;
 
   if (should_be_shown)

ash/home_screen/home_screen_controller_unittest.cc

@@ -6,11 +6,16 @@
 
 #include <memory>
 
+#include "ash/app_list/app_list_controller_impl.h"
+#include "ash/home_screen/home_screen_delegate.h"
+#include "ash/public/cpp/test/shell_test_api.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
+#include "ash/wm/overview/overview_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "ash/wm/window_state.h"
 #include "base/macros.h"
+#include "ui/aura/window.h"
 
 namespace ash {
 namespace {
@@ -49,5 +54,25 @@ TEST_F(HomeScreenControllerTest, OnlyMinimizeCycleListWindows) {
   ASSERT_FALSE(WindowState::Get(w2.get())->IsMinimized());
 }
 
+// Tests that the home screen is visible after rotating the screen in overview
+// mode.
+TEST_F(HomeScreenControllerTest,
+       HomeScreenVisibleAfterDisplayUpdateInOverview) {
+  Shell::Get()->tablet_mode_controller()->SetEnabledForTest(true);
+  OverviewController* overview_controller = Shell::Get()->overview_controller();
+  overview_controller->StartOverview();
+
+  // Trigger a display configuration change, this simulates screen rotation.
+  Shell::Get()->app_list_controller()->OnDisplayConfigurationChanged();
+
+  // End overview mode, the home launcher should be visible.
+  overview_controller->EndOverview();
+  ShellTestApi().WaitForOverviewAnimationState(
+      OverviewAnimationState::kExitAnimationComplete);
+
+  EXPECT_TRUE(
+      home_screen_controller()->delegate()->GetHomeScreenWindow()->IsVisible());
+}
+
 }  // namespace
 }  // namespace ash