Introduce chrome://flags/#network-prediction-options-for-service-worker

chrome/browser/net/predictor_tab_helper.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_NET_PREDICTOR_TAB_HELPER_H_
 #define CHROME_BROWSER_NET_PREDICTOR_TAB_HELPER_H_
 
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/reload_type.h"
+#include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace content {
 class NavigationHandle;
 }
 
 namespace chrome_browser_net {
 
 class PredictorTabHelper
     : public content::WebContentsObserver,
       public content::WebContentsUserData<PredictorTabHelper> {
  public:
   ~PredictorTabHelper() override;
 
   // content::WebContentsObserver:
   void DidStartNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidStartNavigationToPendingEntry(
       const GURL& url,
       content::ReloadType reload_type) override;
   void DocumentOnLoadCompletedInMainFrame() override;
 
  private:
   explicit PredictorTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<PredictorTabHelper>;
 
+  void HandleNavigation(const GURL& url);
+  void DidStartServiceWorkerForNavigationPreconnect(
+      const GURL& url,
+      content::StartServiceWorkerForNavigationHintResult result);
   void PreconnectUrl(const GURL& url);
 
   // This boolean is set to true after a call to
   // DidStartNavigationToPendingEntry, which fires off predictive preconnects.
   // This ensures that the resulting call to DidStartNavigation does not
   // duplicate these preconnects. The tab helper spawns preconnects on the
   // navigation to the pending entry because DidStartNavigation is called after
   // render process spawn (pre-PlzNavigate), which can take substantial time
   // especially on Android.
   bool predicted_from_pending_entry_;
 
+  base::WeakPtrFactory<PredictorTabHelper> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PredictorTabHelper);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_PREDICTOR_TAB_HELPER_H_