Ash system tray bubble: Send accessibility event when bubble updates.

When the system tray bubble updates, we should notify accessibility
features too (namely switch access).

with ChromeVox.

Bug: 1105196
AX-Relnotes: N/A
Test: Manual; test that bug is fixed for switch access and still works
Change-Id: I5a48d43601502846de9b7acf934a02370d0b5c52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2360558
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799227}

ash/system/unified/unified_system_tray_bubble.cc

@@ -107,7 +107,7 @@ UnifiedSystemTrayBubble::UnifiedSystemTrayBubble(UnifiedSystemTray* tray,
   bubble_view_->InitializeAndShowBubble();
 
   // Notify accessibility features that the status tray has opened.
-  bubble_view_->NotifyAccessibilityEvent(ax::mojom::Event::kShow, true);
+  NotifyAccessibilityEvent(ax::mojom::Event::kShow, true);
 
   tray->tray_event_filter()->AddBubble(this);
   tray->shelf()->AddObserver(this);
@@ -354,4 +354,9 @@ void UnifiedSystemTrayBubble::SetFrameVisible(bool visible) {
   bubble_widget_->non_client_view()->frame_view()->SetVisible(visible);
 }
 
+void UnifiedSystemTrayBubble::NotifyAccessibilityEvent(ax::mojom::Event event,
+                                                       bool send_native_event) {
+  bubble_view_->NotifyAccessibilityEvent(event, send_native_event);
+}
+
 }  // namespace ash

ash/system/unified/unified_system_tray_bubble.h

@@ -15,6 +15,7 @@
 #include "base/macros.h"
 #include "base/optional.h"
 #include "base/time/time.h"
+#include "ui/accessibility/ax_enums.mojom.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/views/widget/widget_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
@@ -99,6 +100,9 @@ class ASH_EXPORT UnifiedSystemTrayBubble
   // Called when the message center widget is activated.
   void OnMessageCenterActivated();
 
+  // Fire a notification that an accessibility event has occured on this object.
+  void NotifyAccessibilityEvent(ax::mojom::Event event, bool send_native_event);
+
   // TrayBubbleBase:
   TrayBackgroundView* GetTray() const override;
   TrayBubbleView* GetBubbleView() const override;

ash/system/unified/unified_system_tray_controller.cc

@@ -51,6 +51,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/numerics/ranges.h"
+#include "ui/accessibility/ax_enums.mojom.h"
 #include "ui/compositor/animation_metrics_reporter.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/message_center/message_center.h"
@@ -459,8 +460,11 @@ void UnifiedSystemTrayController::ShowDetailedView(
   detailed_view_controller_ = std::move(controller);
 
   // |bubble_| may be null in tests.
-  if (bubble_)
+  if (bubble_) {
     bubble_->UpdateBubble();
+    // Notify accessibility features that a new view is showing.
+    bubble_->NotifyAccessibilityEvent(ax::mojom::Event::kShow, true);
+  }
 }
 
 void UnifiedSystemTrayController::UpdateExpandedAmount() {