Keep track of fixed positioning in accessibility tree.

third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h

Index: third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h
diff --git a/third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h b/third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h
index a52ba7071f605e811be7c971595a67585c90867a..07390994c208c1ee7a464af421fe90f989e56aa8 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h
+++ b/third_party/WebKit/Source/modules/accessibility/AXImageMapLink.h
@@ -64,7 +64,8 @@ class AXImageMapLink final : public AXNodeObject {
   AXObject* ComputeParent() const override;
   void GetRelativeBounds(AXObject** out_container,
                          FloatRect& out_bounds_in_container,
-                         SkMatrix44& out_container_transform) const override;
+                         SkMatrix44& out_container_transform,
+                         bool& out_is_fixed_positioned) const override;
 
  private:
   bool IsImageMapLink() const override { return true; }