Implement accessibility support for CSS-transformed iframes.

ui/accessibility/ax_node_data.h

Index: ui/accessibility/ax_node_data.h
diff --git a/ui/accessibility/ax_node_data.h b/ui/accessibility/ax_node_data.h
index 16168aadc09e5076a39aaf0a909948f948daa20d..f44618192d84ad38e41e5f283b7c03aaeb8e45af 100644
--- a/ui/accessibility/ax_node_data.h
+++ b/ui/accessibility/ax_node_data.h
@@ -17,6 +17,10 @@
 #include "ui/accessibility/ax_export.h"
 #include "ui/gfx/geometry/rect.h"
 
+namespace gfx {
+class Transform;
+};
+
 namespace ui {
 
 // A compact representation of the accessibility information for a
@@ -102,7 +106,6 @@ struct AX_EXPORT AXNodeData {
   int32_t id;
   AXRole role;
   uint32_t state;
-  gfx::Rect location;
   std::vector<std::pair<AXStringAttribute, std::string> > string_attributes;
   std::vector<std::pair<AXIntAttribute, int32_t>> int_attributes;
   std::vector<std::pair<AXFloatAttribute, float> > float_attributes;
@@ -111,6 +114,16 @@ struct AX_EXPORT AXNodeData {
       intlist_attributes;
   base::StringPairs html_attributes;
   std::vector<int32_t> child_ids;
+
+  // The object's location relative to its window or frame.
+  gfx::Rect location;
+
+  // An additional transform to apply to position this object and its subtree.
+  // NOTE: this member is a scoped_ptr because it's rare and gfx::Transform
+  // takes up a fair amount of space. The assignment operator and copy
+  // constructor both make a duplicate of the owned pointer, so it acts more
+  // like a member than a pointer.
+  scoped_ptr<gfx::Transform> transform;
 };
 
 }  // namespace ui