assistant: Add web view container

In embedded Assistant UI experiment, we will move the web view to its
own container.

This cl is the first part to add the container. A follow up cl will
handle the back arrow.

Bug: b/141268413
Test: new unittest
Change-Id: I9d3b9663b7a60f02e9f50e0076d9c342c299d8f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1837294
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707946}

ash/BUILD.gn

@@ -209,6 +209,8 @@ component("ash") {
     "assistant/assistant_ui_controller.h",
     "assistant/assistant_view_delegate_impl.cc",
     "assistant/assistant_view_delegate_impl.h",
+    "assistant/assistant_web_ui_controller.cc",
+    "assistant/assistant_web_ui_controller.h",
     "autoclick/autoclick_controller.cc",
     "autoclick/autoclick_controller.h",
     "autoclick/autoclick_drag_event_rewriter.cc",
@@ -1672,6 +1674,7 @@ test("ash_unittests") {
     "assistant/assistant_state_controller_unittest.cc",
     "assistant/model/assistant_query_history_unittest.cc",
     "assistant/ui/assistant_container_view_unittest.cc",
+    "assistant/ui/assistant_web_container_view_unittest.cc",
     "assistant/util/deep_link_util_unittest.cc",
     "autoclick/autoclick_drag_event_rewriter_unittest.cc",
     "autoclick/autoclick_unittest.cc",
@@ -2017,6 +2020,7 @@ test("ash_unittests") {
     # TODO(https://crbug.com/644355): Remove Shill dependencies.
     "//chromeos/network:test_support",
     "//chromeos/services/assistant:test_support",
+    "//chromeos/services/assistant/public:feature_flags",
     "//chromeos/services/assistant/public/cpp:prefs",
     "//chromeos/services/assistant/public/mojom",
     "//chromeos/services/multidevice_setup/public/cpp:test_support",

ash/app_list/BUILD.gn

@@ -118,6 +118,7 @@ component("app_list") {
     "//base/third_party/dynamic_annotations",
     "//cc/paint",
     "//chromeos:chromeos",
+    "//chromeos/services/assistant/public:feature_flags",
     "//components/keyed_service/core",
     "//components/sync",
     "//mojo/public/cpp/bindings",

ash/app_list/views/assistant/assistant_page_view.cc

@@ -22,6 +22,7 @@
 #include "ash/public/cpp/view_shadow.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "base/strings/utf_string_conversions.h"
+#include "chromeos/services/assistant/public/features.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/chromeos/search_box/search_box_constants.h"
 #include "ui/views/background.h"
@@ -78,12 +79,14 @@ void AssistantPageView::InitLayout() {
   SetLayoutManager(std::make_unique<views::FillLayout>());
 
   if (assistant_view_delegate_) {
-    assistant_main_view_ = new AssistantMainView(assistant_view_delegate_);
-    AddChildView(assistant_main_view_);
+    assistant_main_view_ = AddChildView(
+        std::make_unique<AssistantMainView>(assistant_view_delegate_));
 
-    // Web view.
-    assistant_web_view_ = new AssistantWebView(assistant_view_delegate_);
-    AddChildView(assistant_web_view_);
+    // Do not add web view when Assistant web container is enabled.
+    if (!chromeos::assistant::features::IsAssistantWebContainerEnabled()) {
+      assistant_web_view_ = AddChildView(
+          std::make_unique<AssistantWebView>(assistant_view_delegate_));
+    }
 
     // Update the view state based on the current UI mode.
     OnUiModeChanged(assistant_view_delegate_->GetUiModel()->ui_mode(),
@@ -129,8 +132,12 @@ void AssistantPageView::RequestFocus() {
         assistant_main_view_->RequestFocus();
       break;
     case AssistantUiMode::kWebUi:
-      if (assistant_web_view_)
-        assistant_web_view_->RequestFocus();
+      if (!chromeos::assistant::features::IsAssistantWebContainerEnabled()) {
+        if (assistant_web_view_)
+          assistant_web_view_->RequestFocus();
+        break;
+      }
+      NOTREACHED();
       break;
     case AssistantUiMode::kMainUi:
     case AssistantUiMode::kMiniUi:
@@ -249,8 +256,12 @@ void AssistantPageView::OnUiModeChanged(AssistantUiMode ui_mode,
         assistant_main_view_->SetVisible(true);
       break;
     case AssistantUiMode::kWebUi:
-      if (assistant_web_view_)
-        assistant_web_view_->SetVisible(true);
+      if (!chromeos::assistant::features::IsAssistantWebContainerEnabled()) {
+        if (assistant_web_view_)
+          assistant_web_view_->SetVisible(true);
+        break;
+      }
+      NOTREACHED();
       break;
     case AssistantUiMode::kMainUi:
     case AssistantUiMode::kMiniUi:
@@ -296,8 +307,12 @@ int AssistantPageView::GetChildViewHeightForWidth(int width) const {
           height = assistant_main_view_->GetHeightForWidth(width);
         break;
       case AssistantUiMode::kWebUi:
-        if (assistant_web_view_)
-          height = assistant_web_view_->GetHeightForWidth(width);
+        if (!chromeos::assistant::features::IsAssistantWebContainerEnabled()) {
+          if (assistant_web_view_)
+            height = assistant_web_view_->GetHeightForWidth(width);
+          break;
+        }
+        NOTREACHED();
         break;
       case AssistantUiMode::kMainUi:
       case AssistantUiMode::kMiniUi:

ash/assistant/assistant_controller.cc

@@ -8,6 +8,7 @@
 #include <utility>
 
 #include "ash/accessibility/accessibility_controller_impl.h"
+#include "ash/assistant/assistant_web_ui_controller.h"
 #include "ash/assistant/util/deep_link_util.h"
 #include "ash/public/cpp/android_intent_helper.h"
 #include "ash/public/cpp/ash_pref_names.h"
@@ -20,6 +21,7 @@
 #include "base/bind.h"
 #include "base/memory/scoped_refptr.h"
 #include "chromeos/services/assistant/public/cpp/assistant_prefs.h"
+#include "chromeos/services/assistant/public/features.h"
 #include "chromeos/services/assistant/public/mojom/assistant.mojom.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
@@ -33,6 +35,11 @@
 namespace ash {
 
 AssistantController::AssistantController() {
+  if (chromeos::assistant::features::IsAssistantWebContainerEnabled()) {
+    assistant_web_ui_controller_ =
+        std::make_unique<AssistantWebUiController>(this);
+  }
+
   assistant_state_controller_.AddObserver(this);
   chromeos::CrasAudioHandler::Get()->AddAudioObserver(this);
   AddObserver(this);

ash/assistant/assistant_controller.h

@@ -51,6 +51,7 @@ class AssistantSetupController;
 class AssistantStateController;
 class AssistantSuggestionsController;
 class AssistantUiController;
+class AssistantWebUiController;
 
 class ASH_EXPORT AssistantController
     : public chromeos::assistant::mojom::AssistantController,
@@ -145,6 +146,10 @@ class ASH_EXPORT AssistantController
 
   AssistantUiController* ui_controller() { return &assistant_ui_controller_; }
 
+  AssistantWebUiController* web_ui_controller() {
+    return assistant_web_ui_controller_.get();
+  }
+
   AssistantViewDelegate* view_delegate() { return &view_delegate_; }
 
   bool IsAssistantReady() const;
@@ -202,6 +207,7 @@ class ASH_EXPORT AssistantController
   AssistantSetupController assistant_setup_controller_{this};
   AssistantSuggestionsController assistant_suggestions_controller_{this};
   AssistantUiController assistant_ui_controller_{this};
+  std::unique_ptr<AssistantWebUiController> assistant_web_ui_controller_;
 
   AssistantViewDelegateImpl view_delegate_{this};
 

ash/assistant/assistant_ui_controller.cc

@@ -396,6 +396,11 @@ void AssistantUiController::OnAssistantControllerDestroying() {
 void AssistantUiController::OnDeepLinkReceived(
     assistant::util::DeepLinkType type,
     const std::map<std::string, std::string>& params) {
+  // This method only handles web deep links, which will be handled separately
+  // in |AssistantWebUiController| when Assistant web container is enabled.
+  if (chromeos::assistant::features::IsAssistantWebContainerEnabled())
+    return;
+
   if (!assistant::util::IsWebDeepLinkType(type, params))
     return;
 

ash/assistant/assistant_web_ui_controller.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/assistant/assistant_web_ui_controller.h"
+
+#include "ash/assistant/assistant_controller.h"
+#include "ash/assistant/ui/assistant_web_container_view.h"
+#include "ash/assistant/util/deep_link_util.h"
+#include "ash/multi_user/multi_user_window_manager_impl.h"
+#include "ash/session/session_controller_impl.h"
+#include "ash/shell.h"
+#include "chromeos/services/assistant/public/features.h"
+#include "ui/aura/client/aura_constants.h"
+
+namespace ash {
+
+AssistantWebUiController::AssistantWebUiController(
+    AssistantController* assistant_controller)
+    : assistant_controller_(assistant_controller) {
+  DCHECK(chromeos::assistant::features::IsAssistantWebContainerEnabled());
+
+  assistant_controller_->AddObserver(this);
+}
+
+AssistantWebUiController::~AssistantWebUiController() {
+  assistant_controller_->RemoveObserver(this);
+}
+
+void AssistantWebUiController::OnWidgetDestroying(views::Widget* widget) {
+  ResetWebContainerView();
+}
+
+void AssistantWebUiController::OnAssistantControllerDestroying() {
+  if (!web_container_view_)
+    return;
+
+  // The view should not outlive the controller.
+  web_container_view_->GetWidget()->CloseNow();
+  DCHECK_EQ(nullptr, web_container_view_);
+}
+
+void AssistantWebUiController::OnDeepLinkReceived(
+    assistant::util::DeepLinkType type,
+    const std::map<std::string, std::string>& params) {
+  if (!assistant::util::IsWebDeepLinkType(type, params))
+    return;
+
+  ShowUi();
+}
+
+void AssistantWebUiController::ShowUi() {
+  if (!web_container_view_)
+    CreateWebContainerView();
+
+  web_container_view_->GetWidget()->Show();
+}
+
+AssistantWebContainerView* AssistantWebUiController::GetViewForTest() {
+  return web_container_view_;
+}
+
+void AssistantWebUiController::CreateWebContainerView() {
+  DCHECK(!web_container_view_);
+
+  web_container_view_ =
+      new AssistantWebContainerView(assistant_controller_->view_delegate());
+  web_container_view_->GetWidget()->AddObserver(this);
+
+  // Associate the window for Assistant Web UI with the active user in order to
+  // not leak across user sessions.
+  auto* window_manager = MultiUserWindowManagerImpl::Get();
+  if (!window_manager)
+    return;
+
+  const UserSession* active_user_session =
+      Shell::Get()->session_controller()->GetUserSession(0);
+  if (!active_user_session)
+    return;
+
+  web_container_view_->GetWidget()->GetNativeWindow()->SetProperty(
+      aura::client::kCreatedByUserGesture, true);
+  window_manager->SetWindowOwner(
+      web_container_view_->GetWidget()->GetNativeWindow(),
+      active_user_session->user_info.account_id);
+}
+
+void AssistantWebUiController::ResetWebContainerView() {
+  DCHECK(web_container_view_);
+
+  web_container_view_->GetWidget()->RemoveObserver(this);
+  web_container_view_ = nullptr;
+}
+
+}  // namespace ash

ash/assistant/assistant_web_ui_controller.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_ASSISTANT_ASSISTANT_WEB_UI_CONTROLLER_H_
+#define ASH_ASSISTANT_ASSISTANT_WEB_UI_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "ash/assistant/assistant_controller_observer.h"
+#include "base/macros.h"
+#include "ui/views/widget/widget_observer.h"
+
+namespace ash {
+
+class AssistantController;
+class AssistantWebContainerView;
+
+// The class to manage Assistant web container view.
+class ASH_EXPORT AssistantWebUiController : public views::WidgetObserver,
+                                            public AssistantControllerObserver {
+ public:
+  explicit AssistantWebUiController(AssistantController* assistant_controller);
+  ~AssistantWebUiController() override;
+
+  // views::WidgetObserver:
+  void OnWidgetDestroying(views::Widget* widget) override;
+
+  // AssistantControllerObserver:
+  void OnAssistantControllerDestroying() override;
+  void OnDeepLinkReceived(
+      assistant::util::DeepLinkType type,
+      const std::map<std::string, std::string>& params) override;
+
+  AssistantWebContainerView* GetViewForTest();
+
+ private:
+  void ShowUi();
+
+  // Constructs/resets |web_container_view_|.
+  void CreateWebContainerView();
+  void ResetWebContainerView();
+
+  AssistantController* const assistant_controller_;  // Owned by Shell.
+
+  // Owned by view hierarchy.
+  AssistantWebContainerView* web_container_view_ = nullptr;
+
+  DISALLOW_COPY_AND_ASSIGN(AssistantWebUiController);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ASSISTANT_ASSISTANT_WEB_UI_CONTROLLER_H_

ash/assistant/test/assistant_ash_test_base.cc

@@ -45,6 +45,7 @@ void AssistantAshTestBase::SetUp() {
 
 void AssistantAshTestBase::TearDown() {
   AshTestBase::TearDown();
+  scoped_feature_list_.Reset();
   ReenableAnimations();
 }
 

ash/assistant/ui/BUILD.gn

@@ -50,6 +50,8 @@ component("ui") {
     "assistant_notification_view.h",
     "assistant_overlay.h",
     "assistant_view_delegate.h",
+    "assistant_web_container_view.cc",
+    "assistant_web_container_view.h",
     "assistant_web_view.cc",
     "assistant_web_view.h",
     "base/assistant_button.cc",

ash/assistant/ui/DEPS

@@ -23,6 +23,8 @@ specific_include_rules = {
   ".*_unittest\.cc": [
     "+ash/assistant/assistant_controller.h",
     "+ash/assistant/assistant_ui_controller.h",
+    "+ash/assistant/assistant_web_ui_controller.h",
+    "+ash/assistant/test/assistant_ash_test_base.h",
     "+ash/shell.h",
     "+ash/session/session_controller_impl.h",
     "+ash/test/ash_test_base.h",

ash/assistant/ui/assistant_container_view_unittest.cc

@@ -71,10 +71,7 @@ TEST_F(AssistantContainerViewTest, InitialAnchoring) {
 
   // We expect the view to appear in the work area where new windows will open.
   gfx::Rect expected_work_area =
-      display::Screen::GetScreen()
-          ->GetDisplayMatching(
-              Shell::Get()->GetRootWindowForNewWindows()->GetBoundsInScreen())
-          .work_area();
+      display::Screen::GetScreen()->GetPrimaryDisplay().work_area();
 
   // We expect the view to be horizontally centered and bottom aligned.
   gfx::Rect expected_bounds = gfx::Rect(expected_work_area);

ash/assistant/ui/assistant_web_container_view.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/assistant/ui/assistant_web_container_view.h"
+
+#include <algorithm>
+#include <memory>
+
+#include "ash/assistant/ui/assistant_ui_constants.h"
+#include "ash/assistant/ui/assistant_view_delegate.h"
+#include "ash/assistant/ui/assistant_web_view.h"
+#include "ui/display/display.h"
+#include "ui/display/screen.h"
+#include "ui/views/background.h"
+#include "ui/views/layout/fill_layout.h"
+#include "ui/views/window/caption_button_layout_constants.h"
+
+namespace ash {
+
+namespace {
+
+constexpr int kPreferredWindowWidthDip = 768;
+
+// This height includes the window's |non_client_frame_view|'s height.
+constexpr int kPreferredWindowHeightDip = 768;
+
+// The minimum padding of the window to the edges of the screen.
+constexpr int kPreferredPaddingMinDip = 48;
+
+}  // namespace
+
+AssistantWebContainerView::AssistantWebContainerView(
+    AssistantViewDelegate* delegate)
+    : delegate_(delegate) {
+  InitLayout();
+}
+
+AssistantWebContainerView::~AssistantWebContainerView() = default;
+
+const char* AssistantWebContainerView::GetClassName() const {
+  return "AssistantWebContainerView";
+}
+
+gfx::Size AssistantWebContainerView::CalculatePreferredSize() const {
+  // TODO(b/142565300): Handle virtual keyboard resize.
+  const gfx::Rect work_area =
+      display::Screen::GetScreen()
+          ->GetDisplayNearestWindow(GetWidget()->GetNativeWindow())
+          .work_area();
+
+  const int width = std::min(work_area.width() - 2 * kPreferredPaddingMinDip,
+                             kPreferredWindowWidthDip);
+  const int height = std::min(work_area.height() - 2 * kPreferredPaddingMinDip,
+                              kPreferredWindowHeightDip);
+  const int non_client_frame_view_height =
+      views::GetCaptionButtonLayoutSize(
+          views::CaptionButtonLayoutSize::kNonBrowserCaption)
+          .height();
+  return gfx::Size(width, height - non_client_frame_view_height);
+}
+
+void AssistantWebContainerView::InitLayout() {
+  views::Widget::InitParams params;
+  params.type = views::Widget::InitParams::TYPE_WINDOW;
+  params.delegate = this;
+  params.name = GetClassName();
+
+  views::Widget* widget = new views::Widget;
+  widget->Init(std::move(params));
+
+  SetLayoutManager(std::make_unique<views::FillLayout>());
+  SetBackground(views::CreateSolidBackground(SK_ColorWHITE));
+
+  // Web view.
+  AddChildView(std::make_unique<AssistantWebView>(delegate_));
+}
+
+}  // namespace ash

ash/assistant/ui/assistant_web_container_view.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_ASSISTANT_UI_ASSISTANT_WEB_CONTAINER_VIEW_H_
+#define ASH_ASSISTANT_UI_ASSISTANT_WEB_CONTAINER_VIEW_H_
+
+#include "base/component_export.h"
+#include "base/macros.h"
+#include "ui/views/widget/widget_delegate.h"
+
+namespace ash {
+
+class AssistantViewDelegate;
+
+// The container of assistant_web_view when Assistant web container is enabled.
+class COMPONENT_EXPORT(ASSISTANT_UI) AssistantWebContainerView
+    : public views::WidgetDelegateView {
+ public:
+  explicit AssistantWebContainerView(AssistantViewDelegate* delegate);
+  ~AssistantWebContainerView() override;
+
+  // views::WidgetDelegateView:
+  const char* GetClassName() const override;
+  gfx::Size CalculatePreferredSize() const override;
+
+ private:
+  void InitLayout();
+
+  AssistantViewDelegate* const delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(AssistantWebContainerView);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ASSISTANT_UI_ASSISTANT_WEB_CONTAINER_VIEW_H_

ash/assistant/ui/assistant_web_container_view_unittest.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/assistant/ui/assistant_web_container_view.h"
+
+#include "ash/assistant/assistant_controller.h"
+#include "ash/assistant/assistant_ui_controller.h"
+#include "ash/assistant/assistant_web_ui_controller.h"
+#include "ash/assistant/test/assistant_ash_test_base.h"
+#include "ash/public/cpp/assistant/assistant_settings.h"
+#include "ash/shell.h"
+#include "base/macros.h"
+#include "base/test/scoped_feature_list.h"
+#include "chromeos/services/assistant/public/features.h"
+
+namespace ash {
+
+namespace {
+
+class AssistantWebContainerViewTest : public AssistantAshTestBase {
+ public:
+  AssistantWebContainerViewTest() = default;
+  ~AssistantWebContainerViewTest() override = default;
+
+  void SetUp() override {
+    scoped_feature_list_.InitAndEnableFeature(
+        chromeos::assistant::features::kEnableAssistantWebContainer);
+
+    AssistantAshTestBase::SetUp();
+  }
+
+  void TearDown() override {
+    AssistantAshTestBase::TearDown();
+    scoped_feature_list_.Reset();
+  }
+
+ protected:
+  AssistantWebContainerView* view() {
+    return Shell::Get()
+        ->assistant_controller()
+        ->web_ui_controller()
+        ->GetViewForTest();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(AssistantWebContainerViewTest);
+};
+
+}  // namespace
+
+TEST_F(AssistantWebContainerViewTest, ShowAndCloseWindow) {
+  // Show Assistant Settings UI.
+  OpenAssistantSettings();
+  AssistantWebContainerView* container_view = view();
+  ASSERT_TRUE(container_view);
+
+  // Close Assistant Settings UI.
+  container_view->GetWidget()->CloseNow();
+  container_view = view();
+  ASSERT_FALSE(container_view);
+}
+
+TEST_F(AssistantWebContainerViewTest, CenterWindow) {
+  // Test large and small screens.
+  std::vector<std::string> resolutions{"1200x1000", "800x600"};
+
+  for (const auto& resolution : resolutions) {
+    UpdateDisplay(resolution);
+
+    // Show Assistant Settings UI and grab a reference to our view under test.
+    OpenAssistantSettings();
+    AssistantWebContainerView* container_view = view();
+
+    // We expect the view to appear in the work area where new windows will
+    // open.
+    gfx::Rect expected_work_area =
+        display::Screen::GetScreen()->GetPrimaryDisplay().work_area();
+
+    // We expect the view to be centered in screen.
+    gfx::Rect expected_bounds = gfx::Rect(expected_work_area);
+    expected_bounds.ClampToCenteredSize(
+        container_view->GetWidget()->GetNativeWindow()->bounds().size());
+    ASSERT_EQ(expected_bounds,
+              container_view->GetWidget()->GetWindowBoundsInScreen());
+    container_view->GetWidget()->CloseNow();
+  }
+}
+
+}  // namespace ash

ash/assistant/ui/assistant_web_view.cc

@@ -14,6 +14,7 @@
 #include "ash/public/cpp/app_list/app_list_features.h"
 #include "base/bind.h"
 #include "base/callback.h"
+#include "chromeos/services/assistant/public/features.h"
 #include "services/content/public/cpp/navigable_contents_view.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
@@ -32,11 +33,17 @@ AssistantWebView::AssistantWebView(AssistantViewDelegate* delegate)
   InitLayout();
 
   delegate_->AddObserver(this);
-  delegate_->AddUiModelObserver(this);
+
+  // |AssistantWebView| has its own separate container when Assistant web
+  // container is enabled. The container will handle its own lifecycle.
+  if (!chromeos::assistant::features::IsAssistantWebContainerEnabled())
+    delegate_->AddUiModelObserver(this);
 }
 
 AssistantWebView::~AssistantWebView() {
-  delegate_->RemoveUiModelObserver(this);
+  if (!chromeos::assistant::features::IsAssistantWebContainerEnabled())
+    delegate_->RemoveUiModelObserver(this);
+
   delegate_->RemoveObserver(this);
 }
 
@@ -49,6 +56,10 @@ gfx::Size AssistantWebView::CalculatePreferredSize() const {
 }
 
 int AssistantWebView::GetHeightForWidth(int width) const {
+  // The Assistant web container has fixed height.
+  if (chromeos::assistant::features::IsAssistantWebContainerEnabled())
+    return INT_MAX;
+
   if (app_list_features::IsEmbeddedAssistantUIEnabled())
     return kMaxHeightEmbeddedDip;
 
@@ -184,6 +195,10 @@ void AssistantWebView::OnUiVisibilityChanged(
     AssistantVisibility old_visibility,
     base::Optional<AssistantEntryPoint> entry_point,
     base::Optional<AssistantExitPoint> exit_point) {
+  // When Assistant web container is enabled, |assistant_web_view| has its own
+  // container and this method should not be called on it.
+  DCHECK(!chromeos::assistant::features::IsAssistantWebContainerEnabled());
+
   // When the Assistant UI is closed we need to clear the |contents_| in order
   // to free the memory.
   if (new_visibility == AssistantVisibility::kClosed)
@@ -192,6 +207,8 @@ void AssistantWebView::OnUiVisibilityChanged(
 
 void AssistantWebView::OnUsableWorkAreaChanged(
     const gfx::Rect& usable_work_area) {
+  DCHECK(!chromeos::assistant::features::IsAssistantWebContainerEnabled());
+
   UpdateContentSize();
 }
 

chromeos/services/assistant/public/BUILD.gn

@@ -13,6 +13,7 @@ component("feature_flags") {
   ]
 
   deps = [
+    "//ash/public/cpp",
     "//base",
   ]
 }

chromeos/services/assistant/public/features.cc

@@ -4,6 +4,7 @@
 
 #include "chromeos/services/assistant/public/features.h"
 
+#include "ash/public/cpp/app_list/app_list_features.h"
 #include "base/feature_list.h"
 
 namespace chromeos {
@@ -76,6 +77,9 @@ const base::Feature kEnableMediaSessionIntegration{
 const base::Feature kDisableVoiceMatch{"DisableVoiceMatch",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kEnableAssistantWebContainer{
+    "EnableAssistantWebContainer", base::FEATURE_DISABLED_BY_DEFAULT};
+
 int GetProactiveSuggestionsMaxWidth() {
   return kAssistantProactiveSuggestionsMaxWidth.Get();
 }
@@ -152,6 +156,11 @@ bool IsVoiceMatchDisabled() {
   return base::FeatureList::IsEnabled(kDisableVoiceMatch);
 }
 
+bool IsAssistantWebContainerEnabled() {
+  return app_list_features::IsEmbeddedAssistantUIEnabled() &&
+         base::FeatureList::IsEnabled(kEnableAssistantWebContainer);
+}
+
 }  // namespace features
 }  // namespace assistant
 }  // namespace chromeos

chromeos/services/assistant/public/features.h

@@ -85,6 +85,10 @@ extern const base::Feature kEnablePowerManager;
 COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC)
 extern const base::Feature kEnableTextQueriesWithClientDiscourseContext;
 
+// Enables the Assistant web container (e.g. Assistant Settings).
+COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC)
+extern const base::Feature kEnableAssistantWebContainer;
+
 COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC)
 int GetProactiveSuggestionsMaxWidth();
 
@@ -127,8 +131,10 @@ COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC) bool IsStereoAudioInputEnabled();
 
 COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC) bool IsWarmerWelcomeEnabled();
 
+COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC) bool IsVoiceMatchDisabled();
+
 COMPONENT_EXPORT(ASSISTANT_SERVICE_PUBLIC)
-bool IsVoiceMatchDisabled();
+bool IsAssistantWebContainerEnabled();
 
 }  // namespace features
 }  // namespace assistant