a11y: Exclude children of nested keyboard accessible controls from a11y tree.

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 3cb42dca9dab0b6b57422f07348b4cc15293f3fa..30967d3c7d8e2ed8c8cd792891542ffa3a038b1d 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -1323,12 +1323,16 @@ bool View::ExceededDragThreshold(const gfx::Vector2d& delta) {
 
 // Accessibility----------------------------------------------------------------
 
-gfx::NativeViewAccessible View::GetNativeViewAccessible() {
+NativeViewAccessibility* View::GetNativeViewAccessibility() {
   if (!native_view_accessibility_)
     native_view_accessibility_ = NativeViewAccessibility::Create(this);
-  if (native_view_accessibility_)
-    return native_view_accessibility_->GetNativeObject();
-  return NULL;
+  return native_view_accessibility_;
+}
+
+gfx::NativeViewAccessible View::GetNativeViewAccessible() {
+  if (GetNativeViewAccessibility())
+    return GetNativeViewAccessibility()->GetNativeObject();
+  return nullptr;
 }
 
 void View::NotifyAccessibilityEvent(
@@ -1338,10 +1342,8 @@ void View::NotifyAccessibilityEvent(
     ViewsDelegate::GetInstance()->NotifyAccessibilityEvent(this, event_type);
 
   if (send_native_event && GetWidget()) {
-    if (!native_view_accessibility_)
-      native_view_accessibility_ = NativeViewAccessibility::Create(this);
-    if (native_view_accessibility_)
-      native_view_accessibility_->NotifyAccessibilityEvent(event_type);
+    if (GetNativeViewAccessibility())
+      GetNativeViewAccessibility()->NotifyAccessibilityEvent(event_type);
   }
 }