Migrate BrowserAccessibility windows unique id handling to AXPlatformNodeWin.

ui/accessibility/platform/ax_platform_node_win.h

 // Copyright 2015 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 UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
 #define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
 
 #include <atlbase.h>
 #include <atlcom.h>
 #include <oleacc.h>
@@ skipping 259 matching lines @@
     COM_INTERFACE_ENTRY(IAccessibleTable)
     COM_INTERFACE_ENTRY(IAccessibleTable2)
     COM_INTERFACE_ENTRY(IAccessibleTableCell)
     COM_INTERFACE_ENTRY(IServiceProvider)
   END_COM_MAP()
 
   ~AXPlatformNodeWin() override;
 
   // Clear node's current relationships and set them to the default values.
   void CalculateRelationships();
+  static AXPlatformNode* GetFromUniqueId(int32_t unique_id);
+  int32_t unique_id() const { return unique_id_; }
 
   // AXPlatformNode overrides.
   gfx::NativeViewAccessible GetNativeViewAccessible() override;
   void NotifyAccessibilityEvent(ui::AXEvent event_type) override;
 
   // AXPlatformNodeBase overrides.
   void Destroy() override;
   int GetIndexInParent() override;
 
   //
@@ skipping 353 matching lines @@
   int32_t ComputeIA2State();
 
   int32_t ComputeIA2Role();
 
   std::vector<base::string16> ComputeIA2Attributes();
 
   // AXPlatformNodeBase overrides.
   void Dispose() override;
 
  private:
+  int32_t unique_id_;
+
   int MSAAEvent(ui::AXEvent event);
   bool IsWebAreaForPresentationalIframe();
   bool ShouldNodeHaveReadonlyStateByDefault(const AXNodeData& data) const;
   bool ShouldNodeHaveFocusableState(const AXNodeData& data) const;
 
   HRESULT GetStringAttributeAsBstr(
       ui::AXStringAttribute attribute,
       BSTR* value_bstr) const;
 
   // Escapes characters in string attributes as required by the IA2 Spec.
@@ skipping 73 matching lines @@
   void RemoveTargetFromRelation(const base::string16& relation_type,
                                 int target_id);
 
   // Relationships between this node and other nodes.
   std::vector<ui::AXPlatformNodeRelationWin*> relations_;
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_