Views a11y: Implement AXPlatformNode::FromNativeViewAccessible on all platforms.

ui/views/accessibility/native_view_accessibility.cc

Index: ui/views/accessibility/native_view_accessibility.cc
diff --git a/ui/views/accessibility/native_view_accessibility.cc b/ui/views/accessibility/native_view_accessibility.cc
index 409ac5a80e802e46f6db09e2a8bbbb0cbce44b65..ef951d464bd4195ea5dbaed54abe82d324220d11 100644
--- a/ui/views/accessibility/native_view_accessibility.cc
+++ b/ui/views/accessibility/native_view_accessibility.cc
@@ -4,7 +4,11 @@
 
 #include "ui/views/accessibility/native_view_accessibility.h"
 
+#include <memory>
+
+#include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "ui/accessibility/platform/ax_platform_node.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/controls/native/native_view_host.h"
@@ -13,12 +17,11 @@
 
 namespace views {
 
-#if !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
 // static
-NativeViewAccessibility* NativeViewAccessibility::Create(View* view) {
-  return new NativeViewAccessibility(view);
+std::unique_ptr<NativeViewAccessibility> NativeViewAccessibility::CreateForView(
+    View* view) {
+  return base::WrapUnique(Create(view));
 }
-#endif  // !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
 
 NativeViewAccessibility::NativeViewAccessibility(View* view)
     : view_(view),
@@ -38,10 +41,6 @@ gfx::NativeViewAccessible NativeViewAccessibility::GetNativeObject() {
   return ax_node_ ? ax_node_->GetNativeViewAccessible() : nullptr;
 }
 
-void NativeViewAccessibility::Destroy() {
-  delete this;
-}
-
 void NativeViewAccessibility::NotifyAccessibilityEvent(ui::AXEvent event_type) {
   if (ax_node_)
     ax_node_->NotifyAccessibilityEvent(event_type);
@@ -127,10 +126,7 @@ gfx::NativeViewAccessible NativeViewAccessibility::GetParent() {
   if (view_->parent())
     return view_->parent()->GetNativeViewAccessible();
 
-  if (parent_widget_)
-    return parent_widget_->GetRootView()->GetNativeViewAccessible();
-
-  return nullptr;
+  return GetNativeViewAccessibleForWidget();
 }
 
 gfx::Vector2d NativeViewAccessibility::GetGlobalCoordinateOffset() {
@@ -241,6 +237,39 @@ void NativeViewAccessibility::SetParentWidget(Widget* parent_widget) {
   parent_widget_->AddObserver(this);
 }
 
+gfx::NativeViewAccessible
+NativeViewAccessibility::GetNativeViewAccessibleForWidget() {
+  if (parent_widget_)
+    return parent_widget_->GetRootView()->GetNativeViewAccessible();
+  return nullptr;
+}
+
+// static
+NativeViewAccessibility* NativeViewAccessibility::GetForView(View* view) {
+#if defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
+  // Retrieving the gfx::NativeViewAccessible also ensures that a
+  // NativeViewAccessibility exists for the given View.
+  gfx::NativeViewAccessible native_object = view->GetNativeViewAccessible();
+  ui::AXPlatformNode* node =
+      ui::AXPlatformNode::FromNativeViewAccessible(native_object);
+  DCHECK(node);
+  return static_cast<NativeViewAccessibility*>(node->GetDelegate());
+#else
+  // Platforms (currently ChromeOS) without a native implementation also have no
+  // gfx::NativeViewAccessible, so make sure a NativeViewAccessibility exists
+  // and return the instance belonging to |view|.
+  view->GetNativeViewAccessible();
+  return view->native_view_accessibility_.get();
+#endif
+}
+
+#if !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
+// static
+NativeViewAccessibility* NativeViewAccessibility::Create(View* view) {
+  return new NativeViewAccessibility(view);
+}
+#endif  // !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
+
 void NativeViewAccessibility::PopulateChildWidgetVector(
     std::vector<Widget*>* result_child_widgets) {
   // Only attach child widgets to the root view.