One accessibility tree per frame.

chrome/renderer/extensions/automation_internal_custom_bindings.h

 // 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.
 
 #ifndef CHROME_RENDERER_EXTENSIONS_AUTOMATION_INTERNAL_CUSTOM_BINDINGS_H_
 #define CHROME_RENDERER_EXTENSIONS_AUTOMATION_INTERNAL_CUSTOM_BINDINGS_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "chrome/common/extensions/api/automation.h"
 #include "extensions/renderer/object_backed_native_handler.h"
 #include "ipc/ipc_message.h"
 #include "ui/accessibility/ax_tree.h"
 #include "v8/include/v8.h"
 
 struct ExtensionMsg_AccessibilityEventParams;
 
 namespace extensions {
 
+class AutomationInternalCustomBindings;
 class AutomationMessageFilter;
 
 struct TreeCache {
   TreeCache();
   ~TreeCache();
 
   int tab_id;
   int tree_id;
+  int parent_node_id_from_parent_tree;
 
   gfx::Vector2d location_offset;
   ui::AXTree tree;
+  AutomationInternalCustomBindings* owner;
 };
 
 struct TreeChangeObserver {
   int id;
   api::automation::TreeChangeObserverFilter filter;
 };
 
 // The native component of custom bindings for the chrome.automationInternal
 // API.
 class AutomationInternalCustomBindings : public ObjectBackedNativeHandler,
                                          public ui::AXTreeDelegate {
  public:
   explicit AutomationInternalCustomBindings(ScriptContext* context);
 
   ~AutomationInternalCustomBindings() override;
 
   void OnMessageReceived(const IPC::Message& message);
 
   TreeCache* GetTreeCacheFromTreeID(int tree_id);
 
+  ui::AXNode* GetParent(ui::AXNode* node, TreeCache** in_out_cache);
+
   ScriptContext* context() const {
     return ObjectBackedNativeHandler::context();
   }
 
  private:
   // ObjectBackedNativeHandler overrides:
   void Invalidate() override;
 
   // Returns whether this extension has the "interact" permission set (either
   // explicitly or implicitly after manifest parsing).
@@ skipping 106 matching lines @@
       tree_change_observer_overall_filter_;
   std::vector<int> deleted_node_ids_;
   std::vector<int> text_changed_node_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(AutomationInternalCustomBindings);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_AUTOMATION_INTERNAL_CUSTOM_BINDINGS_H_