a11y/Mac: Add screenreader support for SubtleNotificationView announcements.

chrome/browser/ui/views/subtle_notification_view.h

 // Copyright 2016 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 CHROME_BROWSER_UI_VIEWS_SUBTLE_NOTIFICATION_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_SUBTLE_NOTIFICATION_VIEW_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/view.h"
+#include "ui/views/widget/widget_observer.h"
+
+namespace ui {
+struct AXViewState;
+}
 
 namespace views {
 class Link;
 class LinkListener;
 class Widget;
 }
 
 // A transient, transparent notification bubble that appears at the top of the
 // browser window to give the user a short instruction (e.g., "Press Esc to exit
 // full screen"). Unlike a full notification, a subtle notification
 // auto-dismisses after a short period of time. It also has special
 // functionality for displaying keyboard shortcuts (rendering the keys inside a
 // rounded rectangle).
-class SubtleNotificationView : public views::View {
+class SubtleNotificationView : public views::View,
+                               public views::WidgetObserver {
  public:
   explicit SubtleNotificationView(views::LinkListener* link_listener);
   ~SubtleNotificationView() override;
 
   void UpdateContent(const base::string16& instruction_text,
                      const base::string16& link_text);
 
   // Creates a Widget containing a SubtleNotificationView. If |accept_events|,
   // the bubble will intercept mouse events (required if there is a clickable
   // link); if not, events will go through to the underlying window.
   static views::Widget* CreatePopupWidget(gfx::NativeView parent_view,
                                           SubtleNotificationView* view,
                                           bool accept_events);
 
+  // The accessible text for screenreaders to announce on displaying this
+  // notification, which should have unicode characters expanded.
+  void SetAccessibleName(const base::string16& accessible_name);
+
+  // views::View:
+  void GetAccessibleState(ui::AXViewState* state) override;
+
+  // views::WidgetObserver:
+  void OnWidgetClosing(views::Widget* widget) override;
+  void OnWidgetVisibilityChanged(views::Widget* widget, bool visible) override;
+
  private:
   class InstructionView;
 
   // Text displayed in the bubble, with optional keyboard keys.
   InstructionView* instruction_view_;
   // Clickable text link. If there is also an instruction view, this appears
   // after the instruction text.
   views::Link* link_;
 
+  base::string16 accessible_name_;
+
   DISALLOW_COPY_AND_ASSIGN(SubtleNotificationView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_SUBTLE_NOTIFICATION_VIEW_H_