Add about:flags entry for scroll anchoring.

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index b8066fb53c09ff479358c312d9090b87c0a6f42f..9022adb8c2e43af06f16f6cb4f2b01e4c9755a22 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -23,6 +23,10 @@ const base::Feature kDownloadResumption{"DownloadResumption",
 const base::Feature kExperimentalFramework{"ExperimentalFramework",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Scrolls to compensate for layout movements (bit.ly/scroll-anchoring).
+const base::Feature kScrollAnchoring{"ScrollAnchoring",
+                                     base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables token binding
 // (https://www.ietf.org/id/draft-ietf-tokbind-protocol-04.txt).
 const base::Feature kTokenBinding{"token-binding",