RubyNG: Enable the feature by default.

This CL adds base::Feature for LayoutNGRuby runtime flag.  We can
disable the feature by Finch when we find a critical bug of the feature.

Bug: 1069817
Change-Id: I93385fd2e6a67acad7af3e45310e254b6692f504
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2250140
Auto-Submit: Kent Tamura <[email protected]>
Reviewed-by: Chris Harrelson <[email protected]>
Commit-Queue: Chris Harrelson <[email protected]>
Commit-Queue: Kent Tamura <[email protected]>
Cr-Commit-Position: refs/heads/master@{#779663}
diff --git a/third_party/blink/common/features.cc b/third_party/blink/common/features.cc
index 9e23a549..3e1331bb 100644
--- a/third_party/blink/common/features.cc
+++ b/third_party/blink/common/features.cc
@@ -71,6 +71,10 @@
 // Enable LayoutNG.
 const base::Feature kLayoutNG{"LayoutNG", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enable LayoutNGRuby by default. This feature is for a kill switch.
+const base::Feature kLayoutNGRuby{"LayoutNGRuby",
+                                  base::FEATURE_ENABLED_BY_DEFAULT};
+
 const base::Feature kFragmentItem{"FragmentItem",
                                   base::FEATURE_DISABLED_BY_DEFAULT};