Move some AX attrs from AXNodeData to AXTreeData.

content/browser/accessibility/browser_accessibility.cc

Index: content/browser/accessibility/browser_accessibility.cc
diff --git a/content/browser/accessibility/browser_accessibility.cc b/content/browser/accessibility/browser_accessibility.cc
index 00d5f47ecd3a2e9bce32659bc2110e69ce7be93e..3539ebbf4b51b863716f3c7c7962e0cb2bf7ea25 100644
--- a/content/browser/accessibility/browser_accessibility.cc
+++ b/content/browser/accessibility/browser_accessibility.cc
@@ -652,10 +652,9 @@ bool BrowserAccessibility::HasCaret() const {
     return true;
   }
 
-  BrowserAccessibility* root = manager()->GetRoot();
   // The caret is always at the focus of the selection.
-  int32 focus_id;
-  if (!root || !root->GetIntAttribute(ui::AX_ATTR_FOCUS_OBJECT_ID, &focus_id))
+  int32 focus_id = manager()->GetTreeData().sel_focus_object_id;
+  if (focus_id == -1)
     return false;
 
   BrowserAccessibility* focus_object = manager()->GetFromID(focus_id);