AXTreeCombiner no longer needs to convert to global coordinates.

ui/accessibility/ax_tree_combiner.h

 // Copyright 2016 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_AX_TREE_COMBINER_H_
 #define UI_ACCESSIBILITY_AX_TREE_COMBINER_H_
 
 #include <vector>
 
 #include "ui/accessibility/ax_export.h"
 #include "ui/accessibility/ax_tree_update.h"
-#include "ui/gfx/transform.h"
 
 namespace ui {
 
 // This helper class takes multiple accessibility trees that reference each
 // other via tree IDs, and combines them into a single accessibility tree
 // that spans all of them.
 //
 // Since node IDs are relative to each ID, it has to renumber all of the IDs
 // and update all of the attributes that reference IDs of other nodes to
-// ensure they point to the right node. It also applies transformations to
-// local bounding rectangles to make them global.
+// ensure they point to the right node.
 //
 // It also makes sure the final combined tree points to the correct focused
 // node across all of the trees based on the focused tree ID of the root tree.
 class AX_EXPORT AXTreeCombiner {
  public:
   AXTreeCombiner();
   ~AXTreeCombiner();
 
   void AddTree(const AXTreeUpdate& tree, bool is_root);
   bool Combine();
 
   const AXTreeUpdate& combined() { return combined_; }
 
  private:
   int32_t MapId(int32_t tree_id, int32_t node_id);
 
   void ProcessTree(const AXTreeUpdate* tree);
 
   std::vector<ui::AXTreeUpdate> trees_;
   int32_t root_tree_id_ = -1;
   int32_t next_id_ = 1;
   std::map<int32_t, const AXTreeUpdate*> tree_id_map_;
   std::map<std::pair<int32_t, int32_t>, int32_t> tree_id_node_id_map_;
   AXTreeUpdate combined_;
-  gfx::Transform transform_;
 };
 
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_TREE_COMBINER_H_