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

ui/accessibility/platform/ax_platform_node.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 "ui/accessibility/platform/ax_platform_node.h"
 
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "build/build_config.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/platform/ax_platform_node_delegate.h"
 
 namespace ui {
 
 namespace {
 
 using UniqueIdMap = base::hash_map<int32_t, AXPlatformNode*>;
 // Map from each AXPlatformNode's unique id to its instance.
 base::LazyInstance<UniqueIdMap> g_unique_id_map =
     LAZY_INSTANCE_INITIALIZER;
 
 }
 
 #if !defined(PLATFORM_HAS_AX_PLATFORM_NODE_IMPL)
 // static
 AXPlatformNode* AXPlatformNode::Create(AXPlatformNodeDelegate* delegate) {
   return nullptr;
 }
-#endif  // !defined(PLATFORM_HAS_AX_PLATFORM_NODE_IMPL)
 
-#if !defined(OS_WIN)
 // This is the default implementation for platforms where native views
 // accessibility is unsupported or unfinished.
 //
 // static
 AXPlatformNode* AXPlatformNode::FromNativeViewAccessible(
     gfx::NativeViewAccessible accessible) {
   return nullptr;
 }
-#endif
+#endif  // !defined(PLATFORM_HAS_AX_PLATFORM_NODE_IMPL)
 
 // static
 int32_t AXPlatformNode::GetNextUniqueId() {
   static int32_t next_unique_id = 1;
   int32_t unique_id = next_unique_id;
   if (next_unique_id == INT32_MAX)
     next_unique_id = 1;
   else
     next_unique_id++;
 
@@ skipping 17 matching lines @@
 AXPlatformNode* AXPlatformNode::GetFromUniqueId(int32_t unique_id) {
   UniqueIdMap* unique_ids = g_unique_id_map.Pointer();
   auto iter = unique_ids->find(unique_id);
   if (iter != unique_ids->end())
     return iter->second;
 
   return nullptr;
 }
 
 }  // namespace ui