service worker: Add NavigationPreload runtime flag and skeleton interface

third_party/WebKit/Source/modules/serviceworkers/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//third_party/WebKit/Source/modules/modules.gni")
 
 blink_modules_sources("serviceworkers") {
   sources = [
     "ExtendableEvent.cpp",
     "ExtendableEvent.h",
     "ExtendableMessageEvent.cpp",
     "ExtendableMessageEvent.h",
     "FetchEvent.cpp",
     "FetchEvent.h",
     "ForeignFetchEvent.cpp",
     "ForeignFetchEvent.h",
     "ForeignFetchRespondWithObserver.cpp",
     "ForeignFetchRespondWithObserver.h",
     "InstallEvent.cpp",
     "InstallEvent.h",
+    "NavigationPreloadManager.cpp",
+    "NavigationPreloadManager.h",
     "NavigatorServiceWorker.cpp",
     "NavigatorServiceWorker.h",
     "RespondWithObserver.cpp",
     "RespondWithObserver.h",
     "ServiceWorker.cpp",
     "ServiceWorker.h",
     "ServiceWorkerClient.cpp",
     "ServiceWorkerClient.h",
     "ServiceWorkerClients.cpp",
     "ServiceWorkerClients.h",
@@ skipping 17 matching lines @@
     "ServiceWorkerScriptCachedMetadataHandler.h",
     "ServiceWorkerThread.cpp",
     "ServiceWorkerThread.h",
     "ServiceWorkerWindowClient.cpp",
     "ServiceWorkerWindowClient.h",
     "ServiceWorkerWindowClientCallback.cpp",
     "ServiceWorkerWindowClientCallback.h",
     "WaitUntilObserver.cpp",
   ]
 }