A11y: Add/refactor methods for manipulating bitfields on AXNodeData.

ash/system/user/button_from_view.cc

 // Copyright 2014 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.
 
 #include <vector>
 
 #include "ash/system/user/button_from_view.h"
 
 #include "ash/ash_constants.h"
 #include "ash/system/tray/tray_constants.h"
@@ skipping 61 matching lines @@
   // Removing focus frame.
   SchedulePaint();
 }
 
 void ButtonFromView::GetAccessibleNodeData(ui::AXNodeData* node_data) {
   views::CustomButton::GetAccessibleNodeData(node_data);
   // If no label has been explicitly set via CustomButton::SetAccessibleName(),
   // use the content's label.
   if (node_data->GetStringAttribute(ui::AX_ATTR_NAME).empty()) {
     ui::AXNodeData content_data;
+    content_data.ClearBitfields();
     content_->GetAccessibleNodeData(&content_data);
     node_data->SetName(content_data.GetStringAttribute(ui::AX_ATTR_NAME));
   }
 }
 
 void ButtonFromView::Layout() {
   CustomButton::Layout();
   if (ink_drop_container_)
     ink_drop_container_->SetBoundsRect(GetLocalBounds());
 }
@@ skipping 32 matching lines @@
 ButtonFromView::CreateInkDropHighlight() const {
   return TrayPopupUtils::CreateInkDropHighlight(ink_drop_style_, this);
 }
 
 std::unique_ptr<views::InkDropMask> ButtonFromView::CreateInkDropMask() const {
   return TrayPopupUtils::CreateInkDropMask(ink_drop_style_, this);
 }
 
 }  // namespace tray
 }  // namespace ash