Keep track of fixed positioning in accessibility tree.

ui/accessibility/ax_relative_bounds.cc

 // 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.
 
 #include "ui/accessibility/ax_relative_bounds.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "ui/gfx/transform.h"
 
 using base::IntToString;
 
 namespace ui {
 
 AXRelativeBounds::AXRelativeBounds()
-    : offset_container_id(-1) {
-}
+    : offset_container_id(-1), is_fixed_positioned(false) {}
 
 AXRelativeBounds::~AXRelativeBounds() {
 }
 
 AXRelativeBounds::AXRelativeBounds(const AXRelativeBounds& other) {
   offset_container_id = other.offset_container_id;
   bounds = other.bounds;
   if (other.transform)
     transform.reset(new gfx::Transform(*other.transform));
+  is_fixed_positioned = other.is_fixed_positioned;
 }
 
 AXRelativeBounds& AXRelativeBounds::operator=(AXRelativeBounds other) {
   offset_container_id = other.offset_container_id;
   bounds = other.bounds;
   if (other.transform)
     transform.reset(new gfx::Transform(*other.transform));
+  is_fixed_positioned = other.is_fixed_positioned;
   return *this;
 }
 
 bool AXRelativeBounds::operator==(const AXRelativeBounds& other) {
   if (offset_container_id != other.offset_container_id)
     return false;
   if (bounds != other.bounds)
     return false;
+  if (is_fixed_positioned != other.is_fixed_positioned)
+    return false;
   if (!transform && !other.transform)
     return true;
   if ((transform && !other.transform) || (!transform && other.transform))
     return false;
   return *transform == *other.transform;
 }
 
 bool AXRelativeBounds::operator!=(const AXRelativeBounds& other) {
   return !operator==(other);
 }
 
 std::string AXRelativeBounds::ToString() const {
   std::string result;
 
   if (offset_container_id != -1)
     result += "offset_container_id=" + IntToString(offset_container_id) + " ";
 
   result += "(" + IntToString(bounds.x()) + ", " +
       IntToString(bounds.y()) + ")-(" +
       IntToString(bounds.width()) + ", " +
       IntToString(bounds.height()) + ")";
 
   if (transform && !transform->IsIdentity())
     result += " transform=" + transform->ToString();
 
+  if (is_fixed_positioned)
+    result += " is_fixed_positioned";
+
   return result;
 }
 
 }  // namespace ui