Fix wrong triggering Logout timer.

This fixes the issue when ARC++ window goes in/out full-screen or
minimized/restored. In this case a window is removed deep inside
the top ARC++ window and this triggers the wrong logout time
activation.
On removing l
This CL checks removing window that belongs to tracked top windows and
ignored hierarchy change events for other child windows.

Test: Manually + unit test
Bug: b/79169326
Change-Id: I825dd9d16d32ce305d43003fb2e77194cfc5ca7c
Reviewed-on: https://chromium-review.googlesource.com/1045827
Commit-Queue: Yury Khmel <khmel@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559155}

ash/system/session/logout_confirmation_controller.cc

@@ -71,20 +71,29 @@ class LogoutConfirmationController::LastWindowClosedObserver
   // Shows the logout confirmation dialog if the last window is closing in the
   // containers we are tracking. Called before closing instead of after closed
   // because aura::WindowObserver only provides notifications to parent windows
-  // before a child is removed, not after.
-  void ShowDialogIfLastWindowClosing() {
-    size_t window_count = 0u;
+  // before a child is removed, not after. Note that removing window deep inside
+  // tracked container also causes OnWindowHierarchyChanging calls so we check
+  // here that removing window is the last window with parent of a tracked
+  // container.
+  void ShowDialogIfLastWindowClosing(const aura::Window* closing_window) {
+    // Enumerate all root windows.
     for (aura::Window* root : Shell::GetAllRootWindows()) {
-      for (int id : kLastWindowClosedContainerIds)
-        window_count += root->GetChildById(id)->children().size();
+      // For each root window enumerate tracked containers.
+      for (int id : kLastWindowClosedContainerIds) {
+        // In each container try to find child window that is not equal to
+        // |closing_window| which would indicate that we have other top-level
+        // window and logout time does not apply.
+        for (const aura::Window* window : root->GetChildById(id)->children()) {
+          if (window != closing_window)
+            return;
+        }
+      }
     }
 
-    // Prompt if the last window is closing.
-    if (window_count == 1) {
-      Shell::Get()->logout_confirmation_controller()->ConfirmLogout(
-          base::TimeTicks::Now() +
-          base::TimeDelta::FromSeconds(kLogoutConfirmationDelayInSeconds));
-    }
+    // No more windows except currently removing. Show logout time.
+    Shell::Get()->logout_confirmation_controller()->ConfirmLogout(
+        base::TimeTicks::Now() +
+        base::TimeDelta::FromSeconds(kLogoutConfirmationDelayInSeconds));
   }
 
   // ShellObserver:
@@ -96,7 +105,7 @@ class LogoutConfirmationController::LastWindowClosedObserver
   void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override {
     if (!params.new_parent && params.old_parent) {
       // A window is being removed (and not moved to another container).
-      ShowDialogIfLastWindowClosing();
+      ShowDialogIfLastWindowClosing(params.target);
     }
   }
 

ash/system/session/logout_confirmation_controller_unittest.cc

@@ -214,6 +214,30 @@ TEST_F(LastWindowClosedTest, PublicSession) {
   EXPECT_TRUE(controller->dialog_for_testing());
 }
 
+// Test ARC++ window hierarchy where window minimize, restore and go in/out full
+// screen causes a window removing deep inside the top window hierarchy. Actions
+// above should no cause logout timer and only closing the last top window
+// triggers the logout timer.
+TEST_F(LastWindowClosedTest, PublicSessionComplexHierarchy) {
+  LogoutConfirmationController* controller =
+      Shell::Get()->logout_confirmation_controller();
+
+  StartPublicAccountSession();
+  EXPECT_FALSE(controller->dialog_for_testing());
+
+  std::unique_ptr<aura::Window> window = CreateToplevelTestWindow();
+  EXPECT_FALSE(controller->dialog_for_testing());
+
+  std::unique_ptr<aura::Window> window_child = CreateChildWindow(window.get());
+  EXPECT_FALSE(controller->dialog_for_testing());
+
+  window_child.reset();
+  EXPECT_FALSE(controller->dialog_for_testing());
+
+  window.reset();
+  EXPECT_TRUE(controller->dialog_for_testing());
+}
+
 TEST_F(LastWindowClosedTest, AlwaysOnTop) {
   LogoutConfirmationController* controller =
       Shell::Get()->logout_confirmation_controller();