Update launcher "hide continue section" feature to new UX spec

This CL updates the clamshell mode launcher:
- The "Continue where you left off" label now always shows (even when
  the privacy toast is showing).
- A new "continue label container" is added to AppListBubbleAppsPage
  to hold both the continue label and the toggle continue section
  button.
- IconButton is updated to support "tiny" buttons (circle size 24x24)
  and custom vector icon sizes (the chevrons are supposed to be 16x16).

Screenshots:
https://screenshot.googleplex.com/7RXbf4GQxKJhNFd
https://screenshot.googleplex.com/5vNnVdQKaU5A75Y
https://screenshot.googleplex.com/3BcBJgAnq2DBANK

TODO: Update the feature for tablet mode
TODO: Animations

Bug: 1334337
Test: updated ash_unittests
Change-Id: Ic888ea00e8be92ec115d2311c7f9c255810987cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3699110
Reviewed-by: Toni Barzic <tbarzic@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1014199}

ash/app_list/views/app_list_bubble_apps_page.cc

@@ -30,7 +30,7 @@
 #include "ash/public/cpp/style/color_provider.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/strings/grit/ash_strings.h"
-#include "ash/style/pill_button.h"
+#include "ash/style/icon_button.h"
 #include "base/bind.h"
 #include "base/check.h"
 #include "base/metrics/histogram_functions.h"
@@ -55,6 +55,7 @@
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/layout/box_layout.h"
+#include "ui/views/view_class_properties.h"
 #include "ui/views/widget/widget.h"
 
 using views::BoxLayout;
@@ -72,6 +73,9 @@ constexpr auto kVerticalScrollInsets = gfx::Insets::TLBR(1, 0, 1, 1);
 // interior apps page container margin.
 constexpr int kVerticalPaddingBetweenSections = 16;
 
+// Label container padding in DIPs.
+constexpr auto kContinueLabelContainerPadding = gfx::Insets::TLBR(0, 16, 0, 16);
+
 // The horizontal interior margin for the apps page container - i.e. the margin
 // between the apps page bounds and the page content.
 constexpr int kHorizontalInteriorMargin = 16;
@@ -160,25 +164,11 @@ AppListBubbleAppsPage::AppListBubbleAppsPage(
       kVerticalPaddingBetweenSections));
   layout->set_cross_axis_alignment(BoxLayout::CrossAxisAlignment::kStretch);
 
-  // Add the button to show the continue section, wrapped in a view to center it
-  // horizontally.
-  {
-    auto* container =
-        scroll_contents->AddChildView(std::make_unique<views::View>());
-    auto* layout = container->SetLayoutManager(
-        std::make_unique<BoxLayout>(BoxLayout::Orientation::kVertical));
-    layout->set_cross_axis_alignment(BoxLayout::CrossAxisAlignment::kCenter);
-    show_continue_section_button_ =
-        container->AddChildView(std::make_unique<PillButton>(
-            base::BindRepeating(
-                &AppListBubbleAppsPage::OnPressShowContinueSection,
-                base::Unretained(this)),
-            l10n_util::GetStringUTF16(IDS_ASH_LAUNCHER_SHOW_CONTINUE_SECTION),
-            PillButton::Type::kIcon, &kExpandAllIcon));
-    show_continue_section_button_->SetUseDefaultLabelFont();
-    // Put the icon on the right.
-    show_continue_section_button_->SetHorizontalAlignment(gfx::ALIGN_RIGHT);
-  }
+  // When feature LauncherHideContinueSection is enabled, the "Continue where
+  // you left off" label is in a container that is a child of this view.
+  // Otherwise the label is a child of the ContinueSectionView.
+  if (features::IsLauncherHideContinueSectionEnabled())
+    InitContinueLabelContainer(scroll_contents.get());
 
   // Continue section row.
   continue_section_ =
@@ -188,6 +178,12 @@ AppListBubbleAppsPage::AppListBubbleAppsPage(
   continue_section_->SetBorder(
       views::CreateEmptyBorder(kContinueSectionInsets));
   continue_section_->SetNudgeController(app_list_nudge_controller_.get());
+  if (features::IsLauncherHideContinueSectionEnabled()) {
+    // Decrease the between-sections spacing so the continue label is closer to
+    // the continue tasks section.
+    continue_section_->SetProperty(views::kMarginsKey,
+                                   gfx::Insets::TLBR(-14, 0, 0, 0));
+  }
 
   // Observe changes in continue section visibility, to keep separator
   // visibility in sync.
@@ -289,9 +285,19 @@ void AppListBubbleAppsPage::AnimateShowLauncher(bool is_side_shelf) {
   // build a single animation with conditional parts. https://crbug.com/1266020
   const int section_offset = is_side_shelf ? -20 : 20;
   int vertical_offset = 0;
+  const bool animate_continue_label_container =
+      continue_label_container_ && continue_label_container_->GetVisible();
+  if (animate_continue_label_container) {
+    vertical_offset += section_offset;
+    SlideViewIntoPosition(continue_label_container_, vertical_offset,
+                          slide_duration);
+  }
   if (continue_section_->GetVisible() &&
       continue_section_->GetTasksSuggestionsCount() > 0) {
-    vertical_offset += section_offset;
+    // Only offset if this is the top section, otherwise animate next to the
+    // continue label container above.
+    if (!animate_continue_label_container)
+      vertical_offset += section_offset;
     SlideViewIntoPosition(continue_section_, vertical_offset, slide_duration);
   }
   if (recent_apps_->GetVisible() && recent_apps_->GetItemViewCount() > 0) {
@@ -646,19 +652,74 @@ ui::Layer* AppListBubbleAppsPage::GetPageAnimationLayerForTest() {
   return scroll_view_->contents()->layer();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// private:
+
+void AppListBubbleAppsPage::InitContinueLabelContainer(
+    views::View* scroll_contents) {
+  continue_label_container_ =
+      scroll_contents->AddChildView(std::make_unique<views::View>());
+  continue_label_container_->SetBorder(
+      views::CreateEmptyBorder(kContinueLabelContainerPadding));
+
+  auto* layout = continue_label_container_->SetLayoutManager(
+      std::make_unique<BoxLayout>(BoxLayout::Orientation::kHorizontal));
+  layout->set_cross_axis_alignment(BoxLayout::CrossAxisAlignment::kCenter);
+
+  continue_label_ =
+      continue_label_container_->AddChildView(std::make_unique<views::Label>(
+          l10n_util::GetStringUTF16(IDS_ASH_LAUNCHER_CONTINUE_SECTION_LABEL)));
+  bubble_utils::ApplyStyle(continue_label_,
+                           bubble_utils::LabelStyle::kSubtitle);
+  continue_label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+
+  // Button should be right aligned, so flex label to fill empty space.
+  layout->SetFlexForView(continue_label_, 1);
+
+  toggle_continue_section_button_ =
+      continue_label_container_->AddChildView(std::make_unique<IconButton>(
+          base::BindRepeating(&AppListBubbleAppsPage::OnToggleContinueSection,
+                              base::Unretained(this)),
+          IconButton::Type::kTinyFloating, &kChevronUpIcon,
+          /*is_togglable=*/false,
+          /*has_border=*/false));
+  // The icon is scaled down since the button is tiny.
+  toggle_continue_section_button_->SetIconSize(16);
+}
+
 void AppListBubbleAppsPage::UpdateContinueSectionVisibility() {
-  // Show the "Show continue section" button if the continue section is hidden.
-  bool hide_continue_section = view_delegate_->ShouldHideContinueSection();
-  show_continue_section_button_->SetVisible(hide_continue_section);
   // The continue section view and recent apps view manage their own visibility
   // internally.
   continue_section_->UpdateElementsVisibility();
   recent_apps_->UpdateVisibility();
+  UpdateContinueLabelContainer();
   UpdateSeparatorVisibility();
 }
 
+void AppListBubbleAppsPage::UpdateContinueLabelContainer() {
+  if (!continue_label_container_)
+    return;
+
+  // If there are no suggested tasks and no recent apps, it doesn't make sense
+  // to show the continue label. This can happen for brand-new users.
+  continue_label_container_->SetVisible(
+      continue_section_->GetTasksSuggestionsCount() > 0 ||
+      recent_apps_->GetItemViewCount() > 0);
+
+  // Update the toggle continue section button tooltip and image.
+  bool is_hidden = view_delegate_->ShouldHideContinueSection();
+  toggle_continue_section_button_->SetTooltipText(l10n_util::GetStringUTF16(
+      is_hidden ? IDS_ASH_LAUNCHER_SHOW_CONTINUE_SECTION_TOOLTIP
+                : IDS_ASH_LAUNCHER_HIDE_CONTINUE_SECTION_TOOLTIP));
+  toggle_continue_section_button_->SetVectorIcon(is_hidden ? kChevronDownIcon
+                                                           : kChevronUpIcon);
+}
+
 void AppListBubbleAppsPage::UpdateSeparatorVisibility() {
-  separator_->SetVisible(recent_apps_->GetVisible() ||
+  // The separator only hides if the user has the continue section shown but
+  // there are no suggested tasks and no apps. This is rare.
+  separator_->SetVisible(view_delegate_->ShouldHideContinueSection() ||
+                         recent_apps_->GetVisible() ||
                          continue_section_->GetVisible());
 }
 
@@ -819,9 +880,10 @@ void AppListBubbleAppsPage::SlideViewIntoPosition(views::View* view,
                         kSlideAnimationTweenType, cleanup);
 }
 
-void AppListBubbleAppsPage::OnPressShowContinueSection(const ui::Event& event) {
-  view_delegate_->SetHideContinueSection(false);
-  UpdateContinueSectionVisibility();
+void AppListBubbleAppsPage::OnToggleContinueSection() {
+  bool should_hide = !view_delegate_->ShouldHideContinueSection();
+  view_delegate_->SetHideContinueSection(should_hide);
+  // AppListControllerImpl will trigger UpdateContinueSectionVisibility().
 }
 
 BEGIN_METADATA(AppListBubbleAppsPage, views::View)

ash/app_list/views/app_list_bubble_apps_page.h

@@ -28,6 +28,7 @@ class Layer;
 }  // namespace ui
 
 namespace views {
+class Label;
 class Separator;
 }  // namespace views
 
@@ -40,7 +41,7 @@ class AppListFolderController;
 class AppListNudgeController;
 class AppListViewDelegate;
 class ContinueSectionView;
-class PillButton;
+class IconButton;
 class RecentAppsView;
 class RoundedScrollBar;
 class SearchResultPageDialogController;
@@ -151,8 +152,11 @@ class ASH_EXPORT AppListBubbleAppsPage
   // Which layer animates is an implementation detail.
   ui::Layer* GetPageAnimationLayerForTest();
 
-  PillButton* show_continue_section_button_for_test() {
-    return show_continue_section_button_;
+  views::View* continue_label_container_for_test() {
+    return continue_label_container_;
+  }
+  IconButton* toggle_continue_section_button_for_test() {
+    return toggle_continue_section_button_;
   }
   RecentAppsView* recent_apps_for_test() { return recent_apps_; }
   views::Separator* separator_for_test() { return separator_; }
@@ -171,6 +175,14 @@ class ASH_EXPORT AppListBubbleAppsPage
  private:
   friend class AppListTestHelper;
 
+  // Creates the `continue_label_container_` view and its contents, the
+  // continue label and the toggle continue section button.
+  void InitContinueLabelContainer(views::View* scroll_contents);
+
+  // Updates the continue label container and its child views, including the
+  // container visibility and the toggle button state.
+  void UpdateContinueLabelContainer();
+
   void UpdateSeparatorVisibility();
 
   // Destroys the layer for `view`. Not static so it can be used with weak
@@ -206,13 +218,19 @@ class ASH_EXPORT AppListBubbleAppsPage
                              int vertical_offset,
                              base::TimeDelta duration);
 
-  // Button press callback for `show_continue_section_button_`.
-  void OnPressShowContinueSection(const ui::Event& event);
+  // Pressed callback for `toggle_continue_section_button_`.
+  void OnToggleContinueSection();
 
   AppListViewDelegate* view_delegate_ = nullptr;
   views::ScrollView* scroll_view_ = nullptr;
   RoundedScrollBar* scroll_bar_ = nullptr;
-  PillButton* show_continue_section_button_ = nullptr;
+
+  // Wraps both the continue label and the toggle continue section button.
+  // Only exists when feature LauncherHideContinueSection is enabled.
+  views::View* continue_label_container_ = nullptr;
+  views::Label* continue_label_ = nullptr;
+  IconButton* toggle_continue_section_button_ = nullptr;
+
   ContinueSectionView* continue_section_ = nullptr;
   RecentAppsView* recent_apps_ = nullptr;
   views::Separator* separator_ = nullptr;

ash/app_list/views/app_list_bubble_apps_page_unittest.cc

@@ -20,7 +20,7 @@
 #include "ash/constants/ash_features.h"
 #include "ash/public/cpp/app_list/app_list_controller.h"
 #include "ash/shell.h"
-#include "ash/style/pill_button.h"
+#include "ash/style/icon_button.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/layer_animation_stopped_waiter.h"
 #include "base/test/bind.h"
@@ -249,17 +249,27 @@ TEST_F(AppListBubbleAppsPageTest, ContinueSectionVisibleByDefault) {
   helper->AddAppItems(5);
   helper->ShowAppList();
 
-  // The show continue section button is hidden.
-  auto* apps_page = helper->GetBubbleAppsPage();
-  EXPECT_FALSE(
-      apps_page->show_continue_section_button_for_test()->GetVisible());
-
   // The continue section and recent apps are visible.
+  auto* apps_page = helper->GetBubbleAppsPage();
   EXPECT_TRUE(helper->GetBubbleContinueSectionView()->GetVisible());
   EXPECT_TRUE(helper->GetBubbleRecentAppsView()->GetVisible());
   EXPECT_TRUE(apps_page->separator_for_test()->GetVisible());
 }
 
+TEST_F(AppListBubbleAppsPageTest, ContinueLabelHiddenWhenNoTasksAndNoRecents) {
+  base::test::ScopedFeatureList feature_list(
+      features::kLauncherHideContinueSection);
+
+  // Show the app list with no continue suggestions and no recent apps.
+  auto* helper = GetAppListTestHelper();
+  helper->AddAppItems(5);
+  helper->ShowAppList();
+
+  auto* apps_page = helper->GetBubbleAppsPage();
+  ASSERT_TRUE(apps_page->continue_label_container_for_test());
+  EXPECT_FALSE(apps_page->continue_label_container_for_test()->GetVisible());
+}
+
 TEST_F(AppListBubbleAppsPageTest, CanHideContinueSection) {
   base::test::ScopedFeatureList feature_list(
       features::kLauncherHideContinueSection);
@@ -272,19 +282,24 @@ TEST_F(AppListBubbleAppsPageTest, CanHideContinueSection) {
   helper->AddAppItems(5);
   helper->ShowAppList();
 
-  // Hide the continue section.
-  Shell::Get()->app_list_controller()->SetHideContinueSection(true);
-
-  // The show continue section button appears.
+  // The toggle continue section button has the "hide" tooltip.
   auto* apps_page = helper->GetBubbleAppsPage();
-  auto* show_continue_section_button =
-      apps_page->show_continue_section_button_for_test();
-  EXPECT_TRUE(show_continue_section_button->GetVisible());
+  IconButton* toggle_continue_section_button =
+      apps_page->toggle_continue_section_button_for_test();
+  ASSERT_TRUE(toggle_continue_section_button);
+  EXPECT_EQ(toggle_continue_section_button->GetTooltipText(),
+            u"Hide all suggestions");
+
+  // Hide the continue section.
+  LeftClickOn(toggle_continue_section_button);
 
   // Continue section and recent apps are hidden.
   EXPECT_FALSE(helper->GetBubbleContinueSectionView()->GetVisible());
   EXPECT_FALSE(helper->GetBubbleRecentAppsView()->GetVisible());
-  EXPECT_FALSE(apps_page->separator_for_test()->GetVisible());
+
+  // Label container and separator stay visible.
+  EXPECT_TRUE(apps_page->continue_label_container_for_test()->GetVisible());
+  EXPECT_TRUE(apps_page->separator_for_test()->GetVisible());
 }
 
 TEST_F(AppListBubbleAppsPageTest, CanShowContinueSectionByClickingButton) {
@@ -302,22 +317,21 @@ TEST_F(AppListBubbleAppsPageTest, CanShowContinueSectionByClickingButton) {
   helper->AddAppItems(5);
   helper->ShowAppList();
 
-  // The show continue section button appears.
+  // The toggle continue section button has the "show" tooltip.
   auto* apps_page = helper->GetBubbleAppsPage();
-  auto* show_continue_section_button =
-      apps_page->show_continue_section_button_for_test();
-  EXPECT_TRUE(show_continue_section_button->GetVisible());
+  IconButton* toggle_continue_section_button =
+      apps_page->toggle_continue_section_button_for_test();
+  ASSERT_TRUE(toggle_continue_section_button);
+  EXPECT_EQ(toggle_continue_section_button->GetTooltipText(),
+            u"Show all suggestions");
 
   // Continue section and recent apps are hidden.
   EXPECT_FALSE(helper->GetBubbleContinueSectionView()->GetVisible());
   EXPECT_FALSE(helper->GetBubbleRecentAppsView()->GetVisible());
-  EXPECT_FALSE(apps_page->separator_for_test()->GetVisible());
+  EXPECT_TRUE(apps_page->separator_for_test()->GetVisible());
 
   // Click the show continue section button.
-  LeftClickOn(show_continue_section_button);
-
-  // The button hides.
-  EXPECT_FALSE(show_continue_section_button->GetVisible());
+  LeftClickOn(toggle_continue_section_button);
 
   // The continue section and recent apps are visible.
   EXPECT_TRUE(helper->GetBubbleContinueSectionView()->GetVisible());

ash/app_list/views/continue_section_view.cc

@@ -21,6 +21,7 @@
 #include "ash/app_list/views/continue_task_view.h"
 #include "ash/app_list/views/search_result_page_dialog_controller.h"
 #include "ash/bubble/bubble_utils.h"
+#include "ash/constants/ash_features.h"
 #include "ash/public/cpp/app_list/app_list_config.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/session/session_controller_impl.h"
@@ -108,7 +109,9 @@ ContinueSectionView::ContinueSectionView(
                       views::MinimumFlexSizeRule::kScaleToMinimumSnapToZero,
                       views::MaximumFlexSizeRule::kUnbounded));
 
-  if (!tablet_mode) {
+  // The launcher "hide continue section" feature makes the label a child of
+  // AppListBubbleAppsPage.
+  if (!tablet_mode && !features::IsLauncherHideContinueSectionEnabled()) {
     continue_label_ = AddChildView(CreateContinueLabel(
         l10n_util::GetStringUTF16(IDS_ASH_LAUNCHER_CONTINUE_SECTION_LABEL)));
     continue_label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);

ash/ash_strings.grd

@@ -4568,6 +4568,12 @@ Here are some things you can try to get started.
       <message name="IDS_ASH_LAUNCHER_HIDE_CONTINUE_SECTION" desc="Context menu label to hide the launcher continue section (which defaults to being shown).">
         Hide all suggestions
       </message>
+      <message name="IDS_ASH_LAUNCHER_SHOW_CONTINUE_SECTION_TOOLTIP" desc="Tooltip for button that shows the launcher continue section after it has been hidden.">
+        Show all suggestions
+      </message>
+      <message name="IDS_ASH_LAUNCHER_HIDE_CONTINUE_SECTION_TOOLTIP" desc="Tooltip for button that hides the launcher continue section (which defaults to being shown).">
+        Hide all suggestions
+      </message>
       <message name="IDS_ASH_LAUNCHER_CONTINUE_SECTION_PRIVACY_TEXT" desc="Text for the privacy notice of the continue section of the launcher in clamshell mode, which shows recent files and apps that the user can continue using.">
         You’ll see recommendations so you can continue where you left off. You can right-click to remove recommendations.
       </message>

ash/ash_strings_grd/IDS_ASH_LAUNCHER_HIDE_CONTINUE_SECTION_TOOLTIP.png.sha1

@@ -0,0 +1 @@
+ed6eb6890e5465b0c4bd15d923e24f6d34de4bc7

ash/ash_strings_grd/IDS_ASH_LAUNCHER_SHOW_CONTINUE_SECTION_TOOLTIP.png.sha1

@@ -0,0 +1 @@
+52fb662658e02186d2dc3b47a3acff6f85d4dcbe

ash/resources/vector_icons/BUILD.gn

@@ -61,7 +61,9 @@ aggregate_vector_icons("ash_vector_icons") {
     "caret_right.icon",
     "check.icon",
     "check_circle.icon",
+    "chevron_down.icon",
     "chevron_right.icon",
+    "chevron_up.icon",
     "clipboard.icon",
     "clipboard_empty.icon",
     "clipboard_launcher_inner.icon",

ash/resources/vector_icons/chevron_down.icon

@@ -0,0 +1,13 @@
+// Copyright 2022 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.
+
+CANVAS_DIMENSIONS, 20,
+MOVE_TO, 5.41f, 6,
+LINE_TO, 10, 10.95f,
+LINE_TO, 14.59f, 6,
+LINE_TO, 16, 7.52f,
+LINE_TO, 10, 14,
+LINE_TO, 4, 7.52f,
+LINE_TO, 5.41f, 6,
+CLOSE

ash/resources/vector_icons/chevron_up.icon

@@ -0,0 +1,13 @@
+// Copyright 2022 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.
+
+CANVAS_DIMENSIONS, 20,
+MOVE_TO, 5.41f, 14,
+LINE_TO, 10, 9.06f,
+LINE_TO, 14.59f, 14,
+LINE_TO, 16, 12.48f,
+LINE_TO, 10, 6,
+R_LINE_TO, -6, 6.48f,
+LINE_TO, 5.41f, 14,
+CLOSE

ash/style/icon_button.cc

@@ -26,6 +26,7 @@
 namespace ash {
 namespace {
 
+constexpr int kTinyButtonSize = 24;
 constexpr int kSmallButtonSize = 32;
 constexpr int kMediumButtonSize = 36;
 constexpr int kLargeButtonSize = 48;
@@ -41,6 +42,9 @@ constexpr gfx::Insets kFocusRingPadding(1);
 
 int GetButtonSizeOnType(IconButton::Type type) {
   switch (type) {
+    case IconButton::Type::kTiny:
+    case IconButton::Type::kTinyFloating:
+      return kTinyButtonSize;
     case IconButton::Type::kSmall:
     case IconButton::Type::kSmallFloating:
       return kSmallButtonSize;
@@ -54,7 +58,8 @@ int GetButtonSizeOnType(IconButton::Type type) {
 }
 
 bool IsFloatingIconButton(IconButton::Type type) {
-  return type == IconButton::Type::kSmallFloating ||
+  return type == IconButton::Type::kTinyFloating ||
+         type == IconButton::Type::kSmallFloating ||
          type == IconButton::Type::kMediumFloating ||
          type == IconButton::Type::kLargeFloating;
 }
@@ -157,6 +162,13 @@ void IconButton::SetIconColor(const SkColor icon_color) {
   UpdateVectorIcon();
 }
 
+void IconButton::SetIconSize(int size) {
+  if (icon_size_ == size)
+    return;
+  icon_size_ = size;
+  UpdateVectorIcon();
+}
+
 void IconButton::SetToggled(bool toggled) {
   if (!is_togglable_ || toggled_ == toggled)
     return;
@@ -249,6 +261,7 @@ void IconButton::UpdateVectorIcon() {
   const SkColor toggled_icon_color = color_provider->GetContentLayerColor(
       AshColorProvider::ContentLayerType::kButtonIconColorPrimary);
   const SkColor icon_color = toggled_ ? toggled_icon_color : normal_icon_color;
+  const int icon_size = icon_size_.value_or(kIconSize);
 
   // Skip repainting if the incoming icon is the same as the current icon. If
   // the icon has been painted before, |gfx::CreateVectorIcon()| will simply
@@ -256,7 +269,7 @@ void IconButton::UpdateVectorIcon() {
   // assumes that toggled/disabled images changes at the same time as the normal
   // image, which it currently does.
   const gfx::ImageSkia new_normal_image =
-      gfx::CreateVectorIcon(*icon_, kIconSize, icon_color);
+      gfx::CreateVectorIcon(*icon_, icon_size, icon_color);
   const gfx::ImageSkia& old_normal_image =
       GetImage(views::Button::STATE_NORMAL);
   if (!new_normal_image.isNull() && !old_normal_image.isNull() &&
@@ -267,7 +280,7 @@ void IconButton::UpdateVectorIcon() {
   SetImage(views::Button::STATE_NORMAL, new_normal_image);
   SetImage(views::Button::STATE_DISABLED,
            gfx::CreateVectorIcon(
-               *icon_, kIconSize,
+               *icon_, icon_size,
                AshColorProvider::GetDisabledColor(normal_icon_color)));
 }
 

ash/style/icon_button.h

@@ -31,9 +31,11 @@ class ASH_EXPORT IconButton : public views::ImageButton {
   METADATA_HEADER(IconButton);
 
   enum class Type {
+    kTiny,
     kSmall,
     kMedium,
     kLarge,
+    kTinyFloating,
     kSmallFloating,
     kMediumFloating,
     kLargeFloating
@@ -97,6 +99,9 @@ class ASH_EXPORT IconButton : public views::ImageButton {
   // when it's not toggled.
   void SetIconColor(const SkColor icon_color);
 
+  // Sets the size to use for the vector icon in DIPs.
+  void SetIconSize(int size);
+
   // Updates the `toggled_` state of the button.
   void SetToggled(bool toggled);
 
@@ -126,6 +131,9 @@ class ASH_EXPORT IconButton : public views::ImageButton {
   absl::optional<SkColor> background_color_;
   absl::optional<SkColor> icon_color_;
 
+  // Custom value for icon size (usually used to make the icon smaller).
+  absl::optional<int> icon_size_;
+
   DisabledButtonBehavior button_behavior_ = DisabledButtonBehavior::kNone;
 };