Only fallthrough to app list when in clamshell mode.

When overview, splitview and applist are active at the same time,
fallthrough to app list to handle the key events. Otherwise, it should
still be overview to handle the key events.

Bug: 970052, 969899
Change-Id: Ic090a5bc06aeb88ee286bfc35434cd19749e0221
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1642740Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666080}

ash/wm/overview/overview_session.cc

@@ -820,8 +820,11 @@ void OverviewSession::OnKeyEvent(ui::KeyEvent* event) {
   // TODO(crbug.com/952315): Explore better ways to handle this splitview +
   // overview + applist case.
   Shell* shell = Shell::Get();
-  if (shell->app_list_controller() && shell->app_list_controller()->IsVisible())
+  if (shell->app_list_controller() &&
+      shell->app_list_controller()->IsVisible() &&
+      Shell::Get()->split_view_controller()->InClamshellSplitViewMode()) {
     return;
+  }
 
   if (event->type() != ui::ET_KEY_PRESSED)
     return;

ash/wm/overview/overview_session_unittest.cc

@@ -4402,6 +4402,27 @@ TEST_F(SplitViewOverviewSessionTest, ExitOverviewWithOneSnapped) {
   EXPECT_FALSE(InOverviewSession());
 }
 
+// Test that in tablet mode, pressing tab key in overview should not crash.
+TEST_F(SplitViewOverviewSessionTest, NoCrashWhenPressTabKey) {
+  std::unique_ptr<aura::Window> window(CreateWindow(gfx::Rect(400, 400)));
+  std::unique_ptr<aura::Window> window2(CreateWindow(gfx::Rect(400, 400)));
+
+  // In overview, there should be no crash when pressing tab key.
+  ToggleOverview();
+  EXPECT_TRUE(InOverviewSession());
+  SendKey(ui::VKEY_TAB);
+  EXPECT_TRUE(InOverviewSession());
+
+  // When splitview and overview are both active, there should be no crash when
+  // pressing tab key.
+  split_view_controller()->SnapWindow(window.get(), SplitViewController::LEFT);
+  EXPECT_TRUE(InOverviewSession());
+  EXPECT_TRUE(split_view_controller()->InSplitViewMode());
+
+  SendKey(ui::VKEY_TAB);
+  EXPECT_TRUE(InOverviewSession());
+}
+
 // Test the split view and overview functionalities in clamshell mode. Split
 // view is only active when overview is active in clamshell mode.
 class SplitViewOverviewSessionInClamshellTest