Selection API: Do not change focus by Selection functions.

third_party/WebKit/LayoutTests/editing/editing.js

Index: third_party/WebKit/LayoutTests/editing/editing.js
diff --git a/third_party/WebKit/LayoutTests/editing/editing.js b/third_party/WebKit/LayoutTests/editing/editing.js
index fb9a5ecc4945262521801d1f8c71f1d8c8bd0e71..583b10b2076e509f76250f673d9f1b01192dee0e 100644
--- a/third_party/WebKit/LayoutTests/editing/editing.js
+++ b/third_party/WebKit/LayoutTests/editing/editing.js
@@ -927,6 +927,11 @@ function focusOnFirstTextInTestElementIfExists() {
             return null;
         });
 
+        for (var focusTarget = elem; focusTarget; focusTarget = focusTarget.parentNode) {
+            focusTarget.focus();

[yoichio, 2017/02/24 01:54:51]

Why do we need to focus on all ancestors?

[tkent, 2017/02/24 01:59:44]

This just focus on the nearest focusable ancestor.

+            if (focusTarget.ownerDocument.activeElement == focusTarget)
+                break;
+        }
         if (firstVisiblePosition)
             selection.collapse(firstVisiblePosition.node, firstVisiblePosition.offset);
         else