NOT FOR REVIEW. ax tree focus with debugging

chrome/common/extensions/api/automation.idl

Index: chrome/common/extensions/api/automation.idl
diff --git a/chrome/common/extensions/api/automation.idl b/chrome/common/extensions/api/automation.idl
index 96b1d37550897f53848bce9d324857359b9cb75f..da65977e33f378e574574bde487bc5502e72e634 100644
--- a/chrome/common/extensions/api/automation.idl
+++ b/chrome/common/extensions/api/automation.idl
@@ -617,6 +617,10 @@
     // screen views. Note this API is currently only supported on Chrome OS.
     [nocompile] static void getDesktop(RootCallback callback);
 
+    // Get the automation node that currently has focus, globally. Will return
+    // null if none of the nodes in any loaded trees have focus.
+    [nocompile] static AutomationNode getFocus();
+
     // Add a tree change observer. Tree change observers are static/global, they
     // listen to changes across all trees. Pass a filter to determine what
     // specific tree changes to listen to, and note that listnening to all