Revert "Fix UI jank caused by visibility change."

This reverts commit 9bc4c7ef.

Reason for revert: CL fixed UI jank but regressed accessibility. Will re-implement with another approach.

Original change's description:
> Fix UI jank caused by visibility change.
> 
> Previously, when animating the footer view and/or its children, we
> modified visibility so as not to receive focus/accessibility events on
> hidden views.
> 
> Unfortunately, changing the visibility of the footer view has a side
> effect of freeing up space for UiElementContainerView. When this
> happens, there is a bit of UI jank when the UiElementContainerView
> takes that available space when really that space should permanently be
> reserved for the footer. This becomes more obvious in a follow up CL in
> which we add a shadow above the footer.
> 
> Now, we don't modify view visibility. Instead, we update focus behavior
> as appropriate before animations start and after they end.
> 
> See bug for repro steps.
> 
> Bug: b:113871610
> Change-Id: Ic8aa509c722ace44675a3ab7c7e0453c0aa4a352
> Reviewed-on: https://chromium-review.googlesource.com/1197906
> Commit-Queue: David Black <dmblack@google.com>
> Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#588926}

TBR=xiaohuic@chromium.org,dmblack@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: b:113871610
Change-Id: I81f93ff5b641fab87e9b00fffc1c6c428ff44388
Reviewed-on: https://chromium-review.googlesource.com/1216812Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: David Black <dmblack@google.com>
Cr-Commit-Position: refs/heads/master@{#590083}

ash/assistant/ui/main_stage/assistant_footer_view.cc

@@ -75,24 +75,6 @@ void AssistantFooterView::ChildVisibilityChanged(views::View* child) {
   PreferredSizeChanged();
 }
 
-void AssistantFooterView::SetFocusBehavior(FocusBehavior focus_behavior) {
-  switch (focus_behavior) {
-    case FocusBehavior::NEVER:
-      // When focus behavior is NEVER, we update both views.
-      suggestion_container_->SetFocusBehavior(FocusBehavior::NEVER);
-      opt_in_view_->SetFocusBehavior(FocusBehavior::NEVER);
-      break;
-    case FocusBehavior::ALWAYS:
-      // When focus behavior is ALWAYS, we need to respect opt in state.
-      UpdateFocusBehavior();
-      break;
-    case FocusBehavior::ACCESSIBLE_ONLY:
-      // We don't currently use ACCESSIBLE_ONLY focus behavior.
-      NOTREACHED();
-      break;
-  }
-}
-
 void AssistantFooterView::InitLayout() {
   SetLayoutManager(std::make_unique<views::FillLayout>());
 
@@ -100,6 +82,8 @@ void AssistantFooterView::InitLayout() {
   const bool setup_completed =
       Shell::Get()->voice_interaction_controller()->setup_completed();
 
+  LOG(ERROR) << "eyor: setup_completed: " << setup_completed;
+
   // Suggestion container.
   suggestion_container_ = new SuggestionContainerView(assistant_controller_);
   suggestion_container_->set_can_process_events_within_subtree(setup_completed);
@@ -108,6 +92,7 @@ void AssistantFooterView::InitLayout() {
   suggestion_container_->SetPaintToLayer();
   suggestion_container_->layer()->SetFillsBoundsOpaquely(false);
   suggestion_container_->layer()->SetOpacity(setup_completed ? 1.f : 0.f);
+  suggestion_container_->SetVisible(setup_completed);
 
   AddChildView(suggestion_container_);
 
@@ -120,11 +105,9 @@ void AssistantFooterView::InitLayout() {
   opt_in_view_->SetPaintToLayer();
   opt_in_view_->layer()->SetFillsBoundsOpaquely(false);
   opt_in_view_->layer()->SetOpacity(setup_completed ? 0.f : 1.f);
+  opt_in_view_->SetVisible(!setup_completed);
 
   AddChildView(opt_in_view_);
-
-  // Initialize focus behavior.
-  UpdateFocusBehavior(setup_completed);
 }
 
 void AssistantFooterView::OnVoiceInteractionSetupCompleted(bool completed) {
@@ -132,6 +115,8 @@ void AssistantFooterView::OnVoiceInteractionSetupCompleted(bool completed) {
   using assistant::util::CreateOpacityElement;
   using assistant::util::StartLayerAnimationSequence;
 
+  LOG(ERROR) << "eyor: completed: " << completed;
+
   // When the consent state changes, we need to hide/show the appropriate views.
   views::View* hide_view =
       completed ? static_cast<views::View*>(opt_in_view_)
@@ -141,15 +126,14 @@ void AssistantFooterView::OnVoiceInteractionSetupCompleted(bool completed) {
       completed ? static_cast<views::View*>(suggestion_container_)
                 : static_cast<views::View*>(opt_in_view_);
 
-  // Views should not be focusable while they're animating.
-  suggestion_container_->SetFocusBehavior(FocusBehavior::NEVER);
-  opt_in_view_->SetFocusBehavior(FocusBehavior::NEVER);
+  // Reset visibility to enable animation.
+  hide_view->SetVisible(true);
+  show_view->SetVisible(true);
 
   // Hide the view for the previous consent state by fading to 0% opacity.
   StartLayerAnimationSequence(hide_view->layer()->GetAnimator(),
                               CreateLayerAnimationSequence(CreateOpacityElement(
                                   0.f, kAnimationFadeOutDuration)),
-                              // Observe the animation.
                               animation_observer_.get());
 
   // Show the view for the next consent state by fading to 100% opacity with
@@ -182,25 +166,12 @@ bool AssistantFooterView::OnAnimationEnded(
 
   // Only the view relevant to our consent state should process events.
   suggestion_container_->set_can_process_events_within_subtree(setup_completed);
+  suggestion_container_->SetVisible(setup_completed);
   opt_in_view_->set_can_process_events_within_subtree(!setup_completed);
-
-  UpdateFocusBehavior(setup_completed);
+  opt_in_view_->SetVisible(!setup_completed);
 
   // Return false to prevent the observer from destroying itself.
   return false;
 }
 
-void AssistantFooterView::UpdateFocusBehavior(
-    base::Optional<bool> setup_completed) {
-  if (!setup_completed.has_value()) {
-    setup_completed =
-        Shell::Get()->voice_interaction_controller()->setup_completed();
-  }
-
-  suggestion_container_->SetFocusBehavior(
-      setup_completed.value() ? FocusBehavior::ALWAYS : FocusBehavior::NEVER);
-  opt_in_view_->SetFocusBehavior(
-      setup_completed.value() ? FocusBehavior::NEVER : FocusBehavior::ALWAYS);
-}
-
 }  // namespace ash

ash/assistant/ui/main_stage/assistant_footer_view.h

@@ -9,7 +9,6 @@
 
 #include "ash/public/interfaces/voice_interaction_controller.mojom.h"
 #include "base/macros.h"
-#include "base/optional.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "ui/views/view.h"
 
@@ -46,17 +45,12 @@ class AssistantFooterView : public views::View,
       mojom::AssistantAllowedState state) override {}
   void OnLocaleChanged(const std::string& locale) override {}
 
-  void SetFocusBehavior(FocusBehavior focus_behavior);
-
  private:
   void InitLayout();
 
   void OnAnimationStarted(const ui::CallbackLayerAnimationObserver& observer);
   bool OnAnimationEnded(const ui::CallbackLayerAnimationObserver& observer);
 
-  void UpdateFocusBehavior(
-      base::Optional<bool> setup_completed = base::nullopt);
-
   AssistantController* const assistant_controller_;  // Owned by Shell.
 
   SuggestionContainerView* suggestion_container_;  // Owned by view hierarchy.

ash/assistant/ui/main_stage/assistant_main_stage.cc

@@ -648,8 +648,8 @@ void AssistantMainStage::UpdateFooter() {
   // When it is not visible, it should not process events.
   bool visible = !committed_query_view_ && !pending_query_view_;
 
-  // The footer should not be focusable while it's animating.
-  footer_->SetFocusBehavior(FocusBehavior::NEVER);
+  // Reset visibility to enable animation.
+  footer_->SetVisible(true);
 
   if (visible) {
     // The footer will animate up into position so we need to set an initial
@@ -704,8 +704,7 @@ bool AssistantMainStage::OnFooterAnimationEnded(
   // there is no committed or pending query view.
   bool visible = !committed_query_view_ && !pending_query_view_;
   footer_->set_can_process_events_within_subtree(visible);
-  footer_->SetFocusBehavior(visible ? FocusBehavior::ALWAYS
-                                    : FocusBehavior::NEVER);
+  footer_->SetVisible(visible);
 
   // Return false so that the observer does not destroy itself.
   return false;

ash/assistant/ui/main_stage/assistant_opt_in_view.cc

@@ -91,16 +91,6 @@ void AssistantOptInView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   label_->SizeToFit(width());
 }
 
-void AssistantOptInView::ButtonPressed(views::Button* sender,
-                                       const ui::Event& event) {
-  if (delegate_)
-    delegate_->OnOptInButtonPressed();
-}
-
-void AssistantOptInView::SetFocusBehavior(FocusBehavior focus_behavior) {
-  container_->SetFocusBehavior(focus_behavior);
-}
-
 void AssistantOptInView::InitLayout() {
   views::BoxLayout* layout_manager =
       SetLayoutManager(std::make_unique<views::BoxLayout>(
@@ -113,17 +103,18 @@ void AssistantOptInView::InitLayout() {
       views::BoxLayout::MainAxisAlignment::MAIN_AXIS_ALIGNMENT_CENTER);
 
   // Container.
-  container_ = new AssistantOptInContainer(/*listener=*/this);
+  AssistantOptInContainer* container =
+      new AssistantOptInContainer(/*listener=*/this);
 
   layout_manager =
-      container_->SetLayoutManager(std::make_unique<views::BoxLayout>(
+      container->SetLayoutManager(std::make_unique<views::BoxLayout>(
           views::BoxLayout::Orientation::kHorizontal,
           gfx::Insets(0, kPaddingDip)));
 
   layout_manager->set_cross_axis_alignment(
       views::BoxLayout::CrossAxisAlignment::CROSS_AXIS_ALIGNMENT_CENTER);
 
-  AddChildView(container_);
+  AddChildView(container);
 
   // Label.
   label_ = new views::StyledLabel(base::string16(), /*listener=*/nullptr);
@@ -155,10 +146,16 @@ void AssistantOptInView::InitLayout() {
       gfx::Range(offsets.at(1), offsets.at(1) + get_started.length()),
       CreateStyleInfo(gfx::Font::Weight::BOLD));
 
-  container_->AddChildView(label_);
+  container->AddChildView(label_);
+
+  container->SetFocusForPlatform();
+  container->SetAccessibleName(label_text);
+}
 
-  container_->SetFocusForPlatform();
-  container_->SetAccessibleName(label_text);
+void AssistantOptInView::ButtonPressed(views::Button* sender,
+                                       const ui::Event& event) {
+  if (delegate_)
+    delegate_->OnOptInButtonPressed();
 }
 
 }  // namespace ash

ash/assistant/ui/main_stage/assistant_opt_in_view.h

@@ -41,12 +41,9 @@ class AssistantOptInView : public views::View, public views::ButtonListener {
 
   void set_delegate(AssistantOptInDelegate* delegate) { delegate_ = delegate; }
 
-  void SetFocusBehavior(FocusBehavior focus_behavior);
-
  private:
   void InitLayout();
 
-  views::Button* container_;   // Owned by view hierarchy.
   views::StyledLabel* label_;  // Owned by view hierarchy.
 
   AssistantOptInDelegate* delegate_ = nullptr;

ash/assistant/ui/main_stage/suggestion_container_view.cc

@@ -137,7 +137,6 @@ void SuggestionContainerView::OnSuggestionsChanged(
     app_list::SuggestionChipView* suggestion_chip_view =
         new app_list::SuggestionChipView(params, /*listener=*/this);
     suggestion_chip_view->SetAccessibleName(params.text);
-    suggestion_chip_view->SetFocusBehavior(focus_behavior_);
 
     // Given a suggestion chip view, we need to be able to look up the id of
     // the underlying suggestion. This is used for handling press events.
@@ -190,12 +189,6 @@ void SuggestionContainerView::ButtonPressed(views::Button* sender,
       suggestion);
 }
 
-void SuggestionContainerView::SetFocusBehavior(FocusBehavior focus_behavior) {
-  focus_behavior_ = focus_behavior;
-  for (int i = 0; i < content_view()->child_count(); ++i)
-    content_view()->child_at(i)->SetFocusBehavior(focus_behavior);
-}
-
 void SuggestionContainerView::OnUiVisibilityChanged(
     AssistantVisibility new_visibility,
     AssistantVisibility old_visibility,

ash/assistant/ui/main_stage/suggestion_container_view.h

@@ -62,8 +62,6 @@ class SuggestionContainerView : public AssistantScrollView,
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
-  void SetFocusBehavior(FocusBehavior focus_behavior);
-
  private:
   void InitLayout();
 
@@ -76,8 +74,6 @@ class SuggestionContainerView : public AssistantScrollView,
 
   AssistantController* const assistant_controller_;  // Owned by Shell.
 
-  FocusBehavior focus_behavior_ = FocusBehavior::NEVER;
-
   views::BoxLayout* layout_manager_;  // Owned by view hierarchy.
 
   // Cache of suggestion chip views owned by the view hierarchy. The key for the