Change accounts & sync role to be a menu.

The accounts & sync dialog UI is a better fit for the menu accessible
role instead of a dialog, because it contains a list of actionable
buttons instead of a message and a few buttons. What's more, it is
already built using a menu container.

For the dialog to behave like a menu, we need to override the top-level
dialog to become a menu bar, and emit the corresponding events for open
and close to make it discoverable.

Bug: 1098304
Change-Id: I93bb25dc9b790e1f8d0e2c61993d20f191c439c0
AX-relnotes: announce accounts & sync as a menu when opened.
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2494933
Commit-Queue: Jacobo Aragunde Pérez <jaragunde@igalia.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823244}

chrome/browser/ui/views/profiles/profile_menu_view_base.cc

@@ -485,7 +485,10 @@ void ProfileMenuViewBase::ShowBubble(
     bubble = new ProfileMenuView(anchor_button, browser);
   }
 
-  views::BubbleDialogDelegateView::CreateBubble(bubble)->Show();
+  views::Widget* widget = views::BubbleDialogDelegateView::CreateBubble(bubble);
+  bubble->ax_widget_observer_ =
+      std::make_unique<AXMenuWidgetObserver>(bubble, widget);
+  widget->Show();
   if (is_source_keyboard)
     bubble->FocusButtonOnKeyboardOpen();
 }
@@ -987,11 +990,10 @@ void ProfileMenuViewBase::OnThemeChanged() {
 }
 
 ax::mojom::Role ProfileMenuViewBase::GetAccessibleWindowRole() {
-  // Return |ax::mojom::Role::kDialog| which will make screen readers announce
-  // the following in the listed order:
-  // the title of the dialog, labels (if any), the focused View within the
-  // dialog (if any)
-  return ax::mojom::Role::kDialog;
+  // Return |ax::mojom::Role::kMenuBar|, because it fits better the kind of UI
+  // contained in this dialog. The top-level container in this dialog uses a
+  // kMenu role to match.
+  return ax::mojom::Role::kMenuBar;
 }
 
 bool ProfileMenuViewBase::HandleContextMenu(
@@ -1028,3 +1030,31 @@ void ProfileMenuViewBase::UpdateSyncInfoContainerBackground() {
       views::LayoutProvider::Get()->GetCornerRadiusMetric(
           views::EMPHASIS_HIGH)));
 }
+
+// Despite ProfileMenuViewBase being a dialog, we are enforcing it to behave
+// like a menu from the accessibility POV because it fits better with a menu UX.
+// The dialog exposes the kMenuBar role, and the top-level container is kMenu.
+// This class is responsible for emitting menu accessible events when the dialog
+// is activated or deactivated.
+class ProfileMenuViewBase::AXMenuWidgetObserver : public views::WidgetObserver {
+ public:
+  AXMenuWidgetObserver(ProfileMenuViewBase* owner, views::Widget* widget)
+      : owner_(owner) {
+    observer_.Add(widget);
+  }
+  ~AXMenuWidgetObserver() override = default;
+
+  void OnWidgetActivationChanged(views::Widget* widget, bool active) override {
+    if (active) {
+      owner_->NotifyAccessibilityEvent(ax::mojom::Event::kMenuStart, true);
+      owner_->NotifyAccessibilityEvent(ax::mojom::Event::kMenuPopupStart, true);
+    } else {
+      owner_->NotifyAccessibilityEvent(ax::mojom::Event::kMenuPopupEnd, true);
+      owner_->NotifyAccessibilityEvent(ax::mojom::Event::kMenuEnd, true);
+    }
+  }
+
+ private:
+  ProfileMenuViewBase* owner_;
+  ScopedObserver<views::Widget, views::WidgetObserver> observer_{this};
+};

chrome/browser/ui/views/profiles/profile_menu_view_base.h

@@ -169,6 +169,8 @@ class ProfileMenuViewBase : public content::WebContentsDelegate,
   }
 
  private:
+  class AXMenuWidgetObserver;
+
   friend class ProfileMenuViewExtensionsTest;
 
   void Reset();
@@ -222,6 +224,8 @@ class ProfileMenuViewBase : public content::WebContentsDelegate,
   // Actual heading string would be set by children classes.
   base::string16 profile_mgmt_heading_;
 
+  std::unique_ptr<AXMenuWidgetObserver> ax_widget_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileMenuViewBase);
 };