Add verbalization for message center widget

Bug: 1021133
Change-Id: Ic7cbf25c094006efd970c75dff2b733b31620bc1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1974599
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726583}

ash/ash_strings.grd

@@ -1937,6 +1937,9 @@ This file contains the strings for ash.
       </message>
 
       <!-- Message center -->
+      <message name="IDS_ASH_MESSAGE_CENTER_ACCESSIBLE_NAME" desc="The spoken feedback name for when accessible focus moves to the message center">
+        Notification Center
+      </message>
       <message name="IDS_ASH_MESSAGE_CENTER_QUIET_MODE_BUTTON_TOOLTIP" desc="The tooltip text for the do not disturb button.">
         Do not disturb
       </message>

ash/system/message_center/unified_message_center_bubble.cc

@@ -8,6 +8,7 @@
 
 #include "ash/accessibility/accessibility_controller_impl.h"
 #include "ash/shelf/shelf.h"
+#include "ash/strings/grit/ash_strings.h"
 #include "ash/shell.h"
 #include "ash/style/ash_color_provider.h"
 #include "ash/style/default_color_constants.h"
@@ -17,6 +18,7 @@
 #include "ash/system/unified/unified_system_tray.h"
 #include "ash/system/unified/unified_system_tray_bubble.h"
 #include "ash/system/unified/unified_system_tray_view.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/paint_recorder.h"
 #include "ui/views/focus/focus_search.h"
 #include "ui/views/widget/widget.h"
@@ -200,6 +202,10 @@ views::Widget* UnifiedMessageCenterBubble::GetBubbleWidget() const {
   return bubble_widget_;
 }
 
+base::string16 UnifiedMessageCenterBubble::GetAccessibleNameForBubble() {
+  return l10n_util::GetStringUTF16(IDS_ASH_MESSAGE_CENTER_ACCESSIBLE_NAME);
+}
+
 bool UnifiedMessageCenterBubble::ShouldEnableExtraKeyboardAccessibility() {
   return Shell::Get()->accessibility_controller()->spoken_feedback_enabled();
 }

ash/system/message_center/unified_message_center_bubble.h

@@ -66,6 +66,7 @@ class ASH_EXPORT UnifiedMessageCenterBubble : public TrayBubbleBase,
   views::Widget* GetBubbleWidget() const override;
 
   // TrayBubbleView::Delegate:
+  base::string16 GetAccessibleNameForBubble() override;
   bool ShouldEnableExtraKeyboardAccessibility() override;
 
   // views::ViewObserver: