Improve a11y state for ToggleButton.

ui/views/controls/button/toggle_button.cc

Index: ui/views/controls/button/toggle_button.cc
diff --git a/ui/views/controls/button/toggle_button.cc b/ui/views/controls/button/toggle_button.cc
index b872f40b256bcbf573109a450c3ae6dafd0fc6d4..ca6915d5d2ea8b589522d25a94c0e4f458e1cacd 100644
--- a/ui/views/controls/button/toggle_button.cc
+++ b/ui/views/controls/button/toggle_button.cc
@@ -6,6 +6,7 @@
 
 #include "third_party/skia/include/core/SkDrawLooper.h"
 #include "third_party/skia/include/core/SkPaint.h"
+#include "ui/accessibility/ax_node_data.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/color_utils.h"
@@ -201,6 +202,14 @@ void ToggleButton::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   SchedulePaint();
 }
 
+void ToggleButton::GetAccessibleNodeData(ui::AXNodeData* node_data) {
+  CustomButton::GetAccessibleNodeData(node_data);
+
+  node_data->role = ui::AX_ROLE_SWITCH;
+  if (is_on_)
+    node_data->AddStateFlag(ui::AX_STATE_CHECKED);
+}
+
 void ToggleButton::AddInkDropLayer(ui::Layer* ink_drop_layer) {
   thumb_view_->AddInkDropLayer(ink_drop_layer);
 }