Show Accessibility panel over the virtual keyboard

Switch Access (go/cros-switch) uses the Accessibility panel to show its
menu and back button. The back button is currently being shown under
the virtual keyboard, which causes confusion on how to navigate outward
in scope.

A similar change was previously submitted (https://osscs.corp.google.com/chromium/chromium/src/+/0a727234100f0d23e3308767087327f458cc92a3)
but later reverted because of unintended side effects of showing the
ChromeVox panel above fullscreen windows. This change does not have
that affect, as it leaves the logic to hide the window in fullscreen
mode intact.

Bug: 946616
Change-Id: I9f85a5f4f699ea5af55f75a69c1c3f5bb4358c93
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1727511Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/master@{#682911}

ash/accessibility/accessibility_panel_layout_manager.cc

@@ -126,6 +126,9 @@ void AccessibilityPanelLayoutManager::UpdateWindowBounds() {
   if (!always_visible_ && root_controller->GetWindowForFullscreenMode() &&
       !wm::IsActiveWindow(panel_window_)) {
     bounds.set_height(0);
+    panel_window_->SetBounds(bounds);
+    UpdateWorkAreaForPanelHeight();
+    return;
   }
 
   // Make sure the accessibility panel is always below the Docked Magnifier

ash/root_window_controller.cc

@@ -1049,16 +1049,6 @@ void RootWindowController::CreateContainers() {
   settings_bubble_container->SetProperty(::wm::kUsesScreenCoordinatesKey, true);
   settings_bubble_container->SetProperty(kLockedToRootKey, true);
 
-  aura::Window* accessibility_panel_container = CreateContainer(
-      kShellWindowId_AccessibilityPanelContainer, "AccessibilityPanelContainer",
-      lock_screen_related_containers);
-  ::wm::SetChildWindowVisibilityChangesAnimated(accessibility_panel_container);
-  accessibility_panel_container->SetProperty(::wm::kUsesScreenCoordinatesKey,
-                                             true);
-  accessibility_panel_container->SetProperty(kLockedToRootKey, true);
-  accessibility_panel_container->SetLayoutManager(
-      new AccessibilityPanelLayoutManager());
-
   aura::Window* virtual_keyboard_parent_container = CreateContainer(
       kShellWindowId_ImeWindowParentContainer, "ImeWindowParentContainer",
       lock_screen_related_containers);
@@ -1076,6 +1066,16 @@ void RootWindowController::CreateContainers() {
       new keyboard::KeyboardLayoutManager(
           keyboard::KeyboardUIController::Get()));
 
+  aura::Window* accessibility_panel_container = CreateContainer(
+      kShellWindowId_AccessibilityPanelContainer, "AccessibilityPanelContainer",
+      lock_screen_related_containers);
+  ::wm::SetChildWindowVisibilityChangesAnimated(accessibility_panel_container);
+  accessibility_panel_container->SetProperty(::wm::kUsesScreenCoordinatesKey,
+                                             true);
+  accessibility_panel_container->SetProperty(kLockedToRootKey, true);
+  accessibility_panel_container->SetLayoutManager(
+      new AccessibilityPanelLayoutManager());
+
   aura::Window* menu_container =
       CreateContainer(kShellWindowId_MenuContainer, "MenuContainer",
                       lock_screen_related_containers);