Implement automatic load of composed/embedded automation trees

ui/accessibility/ax_enums.idl

Index: ui/accessibility/ax_enums.idl
diff --git a/ui/accessibility/ax_enums.idl b/ui/accessibility/ax_enums.idl
index 5add7a4227431400d49a77c19fc65f15665eb092..07a858304029f5c3e2b63e1f2e1c1a79aaa51d5c 100644
--- a/ui/accessibility/ax_enums.idl
+++ b/ui/accessibility/ax_enums.idl
@@ -294,7 +294,13 @@
     color_value_blue,
 
     // Inline text attributes.
-    text_direction
+    text_direction,
+
+    // TODO(dtseng, dmazzoni): These currently get populated with process and
+    // routing id. Base these ids off of the accessibility tree. Only
+    // applicable to views::WebView.
+    frame_id,
+    child_frame_id
   };
 
   [cpp_enum_prefix_override="ax_attr"] enum AXFloatAttribute {