Introduce ServiceWorkerNavigationPreload feature name

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 426ef7b0cfc8cd1469912ab7c95081d575de0bab..3e2736dbea4523eb05198b1b27ec8d7d7ef1d769 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -157,6 +157,12 @@ const base::Feature kRenderingPipelineThrottling{
 const base::Feature kScrollAnchoring{"ScrollAnchoring",
                                      base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Navigation preload feature of service workers.
+// TODO(horo): Revise link when this lands in the spec:
+// https://github.com/w3c/ServiceWorker/pull/983/files
+const base::Feature kServiceWorkerNavigationPreload{
+    "ServiceWorkerNavigationPreload", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // http://tc39.github.io/ecmascript_sharedmem/shmem.html
 const base::Feature kSharedArrayBuffer{"SharedArrayBuffer",
                                        base::FEATURE_DISABLED_BY_DEFAULT};