Keep track of fixed positioning in accessibility tree.

third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp

Index: third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp b/third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp
index 1e8e30c5498f4b3248645cbbcb7ce375dcfd654c..8d507f071f94061bd3abc91efd59dc769774076e 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXSpinButton.cpp
@@ -101,21 +101,21 @@ AXSpinButtonPart* AXSpinButtonPart::Create(AXObjectCacheImpl& ax_object_cache) {
   return new AXSpinButtonPart(ax_object_cache);
 }
 
-void AXSpinButtonPart::GetRelativeBounds(
+bool AXSpinButtonPart::GetSimpleRelativeBounds(
     AXObject** out_container,
-    FloatRect& out_bounds_in_container,
-    SkMatrix44& out_container_transform) const {
+    FloatRect& out_bounds_in_container) const {
   *out_container = nullptr;
   out_bounds_in_container = FloatRect();
-  out_container_transform.setIdentity();
 
   if (!ParentObject())
-    return;
+    return false;
 
   // FIXME: This logic should exist in the layout tree or elsewhere, but there
   // is no relationship that exists that can be queried.
+  SkMatrix44 container_transform;
+  bool is_fixed_positioned = false;
   ParentObject()->GetRelativeBounds(out_container, out_bounds_in_container,
-                                    out_container_transform);
+                                    container_transform, is_fixed_positioned);
   out_bounds_in_container = FloatRect(0, 0, out_bounds_in_container.Width(),
                                       out_bounds_in_container.Height());
   if (is_incrementor_) {
@@ -126,6 +126,7 @@ void AXSpinButtonPart::GetRelativeBounds(
     out_bounds_in_container.SetHeight(out_bounds_in_container.Height() / 2);
   }
   *out_container = ParentObject();
+  return true;
 }
 
 bool AXSpinButtonPart::Press() {