Keep track of fixed positioning in accessibility tree.

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

Index: third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
index 5976ccf44b0ac11c8c54fd7ffe37b60d541e3fde..7def79a36135ba69b7586494e6065d2321a45ee4 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
@@ -2064,13 +2064,14 @@ bool AXNodeObject::NameFromLabelElement() const {
   return false;
 }
 
-void AXNodeObject::GetRelativeBounds(
-    AXObject** out_container,
-    FloatRect& out_bounds_in_container,
-    SkMatrix44& out_container_transform) const {
+void AXNodeObject::GetRelativeBounds(AXObject** out_container,
+                                     FloatRect& out_bounds_in_container,
+                                     SkMatrix44& out_container_transform,
+                                     bool& out_is_fixed_positioned) const {
   if (LayoutObjectForRelativeBounds()) {
     AXObject::GetRelativeBounds(out_container, out_bounds_in_container,
-                                out_container_transform);
+                                out_container_transform,
+                                out_is_fixed_positioned);
     return;
   }
 
@@ -2099,7 +2100,8 @@ void AXNodeObject::GetRelativeBounds(
         if (AXObject* obj = AxObjectCache().Get(&child)) {
           AXObject* container;
           FloatRect bounds;
-          obj->GetRelativeBounds(&container, bounds, out_container_transform);
+          obj->GetRelativeBounds(&container, bounds, out_container_transform,
+                                 out_is_fixed_positioned);
           if (container) {
             *out_container = container;
             rects.push_back(bounds);
@@ -2122,7 +2124,8 @@ void AXNodeObject::GetRelativeBounds(
        position_provider = position_provider->ParentObject()) {
     if (position_provider->IsAXLayoutObject()) {
       position_provider->GetRelativeBounds(
-          out_container, out_bounds_in_container, out_container_transform);
+          out_container, out_bounds_in_container, out_container_transform,
+          out_is_fixed_positioned);
       if (*out_container)
         out_bounds_in_container.SetSize(
             FloatSize(out_bounds_in_container.Width(),