Introduce Origin-Trial for Service Worker Navigation Preload

content/browser/service_worker/service_worker_version.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 CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
 
 #include <stdint.h>
 
 #include <functional>
@@ skipping 82 matching lines @@
                          // timed out.
   };
 
   // Whether the version has fetch handlers or not.
   enum class FetchHandlerExistence {
     UNKNOWN,  // This version is a new version and not installed yet.
     EXISTS,
     DOES_NOT_EXIST,
   };
 
+  // Navigation Preload support status of the service worker.
+  enum class NavigationPreloadSupportStatus {
+    SUPPORTED,
+    NOT_SUPPORTED_FIELD_TRIAL_STOPPED,
+    NOT_SUPPORTED_DISABLED_BY_COMMAND_LINE,
+    NOT_SUPPORTED_NO_VALID_ORIGIN_TRIAL_TOKEN,
+  };
+
   class Listener {
    public:
     virtual void OnRunningStateChanged(ServiceWorkerVersion* version) {}
     virtual void OnVersionStateChanged(ServiceWorkerVersion* version) {}
     virtual void OnDevToolsRoutingIdChanged(ServiceWorkerVersion* version) {}
     virtual void OnMainScriptHttpResponseInfoSet(
         ServiceWorkerVersion* version) {}
     virtual void OnErrorReported(ServiceWorkerVersion* version,
                                  const base::string16& error_message,
                                  int line_number,
@@ skipping 307 matching lines @@
   // mojom::ServiceWorkerEventDispatcher, once all simple events got dispatched
   // through mojo, OnSimpleEventResponse function could be removed.
   void OnSimpleEventFinished(int request_id,
                              ServiceWorkerStatusCode status,
                              base::Time dispatch_event_time);
 
   void NotifyMainScriptRequestHandlerCreated();
   void NotifyMainScriptJobCreated(
       ServiceWorkerContextRequestHandler::CreateJobStatus status);
 
+  // Returns the Navigation Preload support status of the service worker.
+  //  - Origin Trial: Have an effective token.
+  //                                 Command line
+  //                             Default  Enable  Disabled
+  //                   Default      B1      A        B2
+  //      Field trial  Enabled      A       A        B2
+  //                   Disabled     B1      A        B2
+  //
+  //  - Origin Trial: No token.
+  //                                 Command line
+  //                             Default  Enable  Disabled
+  //                   Default      C       A        C
+  //      Field trial  Enabled      C       A        C
+  //                   Disabled     C       A        C
+  //
+  //   * A  = SUPPORTED
+  //     B1 = NOT_SUPPORTED_FIELD_TRIAL_STOPPED
+  //     B2 = NOT_SUPPORTED_DISABLED_BY_COMMAND_LINE
+  //     C  = NOT_SUPPORTED_NO_VALID_ORIGIN_TRIAL_TOKEN
+  //
+  // There are three types of behaviors:
+  //  - A: Navigation Preload related methods and attributes are available in JS
+  //       and work correctly.
+  //  - B: Navigation Preload related methods and attributes are available in
+  //       JS. But NavigationPreloadManager's enable, disable and setHeaderValue
+  //       methods always return a rejected promise. And FetchEvent's
+  //       preloadResponse attribute returns a promise which always resolve with
+  //       undefined.
+  //  - C: Navigation Preload related methods and attributes are not available
+  //       in JS.
+  // This method returns SUPPORTED only for A case.
+  // blink::OriginTrials::serviceWorkerNavigationPreloadEnabled() returns true
+  // for both A and B case. So the methods and attributes are available in JS.
+  NavigationPreloadSupportStatus GetNavigationPreloadSupportStatus() const;
+
  private:
   friend class base::RefCounted<ServiceWorkerVersion>;
   friend class ServiceWorkerMetrics;
   friend class ServiceWorkerReadFromCacheJobTest;
   friend class ServiceWorkerStallInStoppingTest;
   friend class ServiceWorkerURLRequestJobTest;
   friend class ServiceWorkerVersionBrowserTest;
   friend class ServiceWorkerVersionTest;
 
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerControlleeRequestHandlerTest,
@@ skipping 417 matching lines @@
 
   // At this point |this| can have been deleted, so don't do anything other
   // than returning.
 
   return true;
 }
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_