[Background Sync] Align exposed API with spec

This is the second of a series of commits to align the exposed
BackgroundSync API with the spec at https://wicg.github.io/BackgroundSync/spec/

Part 1: Removing Exposed Periodic Sync: https://crrev.com/1436723002/

BUG=552029

Review URL: https://codereview.chromium.org/1437883002

Cr-Commit-Position: refs/heads/master@{#360068}

21 files changed, 70 insertions, 429 deletions

diff --git a/content/browser/background_sync/background_sync_browsertest.cc b/content/browser/background_sync/background_sync_browsertest.cc
index e3f8dc0..6e30cc5 100644
--- a/content/browser/background_sync/background_sync_browsertest.cc
+++ b/content/browser/background_sync/background_sync_browsertest.cc
@@ -182,8 +182,6 @@ class BackgroundSyncBrowserTest : public ContentBrowserTest {
   bool RegisterServiceWorker();
   bool RegisterOneShot(const std::string& tag);
   bool RegisterOneShotFromServiceWorker(const std::string& tag);
-  bool UnregisterOneShot(const std::string& tag);
-  bool UnregisterOneShotTwice(const std::string& tag);
   bool GetRegistrationOneShot(const std::string& tag);
   bool GetRegistrationOneShotFromServiceWorker(const std::string& tag);
   bool MatchRegistrations(const std::string& script_result,
@@ -193,9 +191,6 @@ class BackgroundSyncBrowserTest : public ContentBrowserTest {
       const std::vector<std::string>& expected_tags);
   bool CompleteDelayedOneShot();
   bool RejectDelayedOneShot();
-  bool NotifyWhenFinishedOneShot(const std::string& tag);
-  bool NotifyWhenFinishedImmediateOneShot(const std::string& expected_msg);
-  bool StoreRegistrationOneShot(const std::string& tag);
 
  private:
   scoped_ptr<net::EmbeddedTestServer> https_server_;
@@ -323,21 +318,6 @@ bool BackgroundSyncBrowserTest::RegisterOneShotFromServiceWorker(
   return script_result == BuildExpectedResult(tag, "register sent to SW");
 }
 
-bool BackgroundSyncBrowserTest::UnregisterOneShot(const std::string& tag) {
-  std::string script_result;
-  EXPECT_TRUE(
-      RunScript(BuildScriptString("unregisterOneShot", tag), &script_result));
-  return script_result == BuildExpectedResult(tag, "unregistered");
-}
-
-bool BackgroundSyncBrowserTest::UnregisterOneShotTwice(const std::string& tag) {
-  std::string script_result;
-  EXPECT_TRUE(RunScript(BuildScriptString("unregisterOneShotTwice", tag),
-                        &script_result));
-  return script_result ==
-         BuildExpectedResult(tag, "failed to unregister twice");
-}
-
 bool BackgroundSyncBrowserTest::GetRegistrationOneShot(const std::string& tag) {
   std::string script_result;
   EXPECT_TRUE(RunScript(BuildScriptString("getRegistrationOneShot", tag),
@@ -400,30 +380,6 @@ bool BackgroundSyncBrowserTest::RejectDelayedOneShot() {
   return script_result == BuildExpectedResult("delay", "rejecting");
 }
 
-bool BackgroundSyncBrowserTest::NotifyWhenFinishedOneShot(
-    const std::string& tag) {
-  EXPECT_TRUE(content::ExecuteScript(
-      shell_->web_contents(),
-      BuildScriptString("notifyWhenFinishedOneShot", tag)));
-  return PopConsole(BuildExpectedResult(tag, "finished"));
-}
-
-bool BackgroundSyncBrowserTest::NotifyWhenFinishedImmediateOneShot(
-    const std::string& expected_msg) {
-  std::string script_result;
-  EXPECT_TRUE(
-      RunScript("notifyWhenFinishedImmediateOneShot()", &script_result));
-  return script_result == expected_msg;
-}
-
-bool BackgroundSyncBrowserTest::StoreRegistrationOneShot(
-    const std::string& tag) {
-  std::string script_result;
-  EXPECT_TRUE(
-      RunScript(BuildScriptString("storeRegistration", tag), &script_result));
-  return script_result == BuildExpectedResult(tag, "stored");
-}
-
 IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, OneShotFires) {
   EXPECT_TRUE(RegisterServiceWorker());
   EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
@@ -477,8 +433,6 @@ IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, WaitUntil) {
   EXPECT_TRUE(PopConsole("ok - delay completed"));
 
   // Verify that it finished firing.
-  // TODO(jkarlin): Use registration.finished to verify that the event actually
-  // completed successfully.
   EXPECT_FALSE(GetRegistrationOneShot("delay"));
 }
 
@@ -586,108 +540,6 @@ IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
   EXPECT_TRUE(GetRegistrationOneShotFromServiceWorker("foo_sw"));
 }
 
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, Unregister) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(false);
-  EXPECT_TRUE(RegisterOneShot("foo"));
-  EXPECT_TRUE(UnregisterOneShot("foo"));
-  EXPECT_FALSE(GetRegistrationOneShot("foo"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, UnregisterTwice) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(false);
-  EXPECT_TRUE(RegisterOneShot("foo"));
-  EXPECT_TRUE(UnregisterOneShotTwice("foo"));
-  EXPECT_FALSE(GetRegistrationOneShot("foo"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, UnregisterMidSync) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  EXPECT_TRUE(RegisterOneShot("unregister"));
-  EXPECT_TRUE(PopConsole("ok - unregister completed"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
-                       CallFinishedBeforeSyncSucceeds) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(false);
-  EXPECT_TRUE(RegisterOneShot("foo"));
-  EXPECT_TRUE(NotifyWhenFinishedOneShot("foo"));
-
-  SetOnline(true);
-  // The ordering of PopConsole messages tells us that the event fired
-  // before finished resolved.
-  EXPECT_TRUE(PopConsole("foo fired"));
-  EXPECT_TRUE(PopConsole("foo finished result: true"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, CallFinishedBeforeSyncFails) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(true);
-  EXPECT_TRUE(RegisterOneShot("delay"));
-  EXPECT_FALSE(OneShotPending("delay"));
-  EXPECT_TRUE(NotifyWhenFinishedOneShot("delay"));
-
-  EXPECT_TRUE(RejectDelayedOneShot());
-  // The ordering of PopConsole messages tells us that the event fired
-  // before finished resolved.
-  EXPECT_TRUE(PopConsole("ok - delay rejected"));
-  EXPECT_TRUE(PopConsole("delay finished result: false"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
-                       CallFinishedAfterSyncSucceeds) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(false);
-  EXPECT_TRUE(RegisterOneShot("foo"));
-  EXPECT_TRUE(StoreRegistrationOneShot("foo"));
-
-  SetOnline(true);
-  EXPECT_TRUE(PopConsole("foo fired"));
-  EXPECT_FALSE(GetRegistrationOneShot("foo"));
-  EXPECT_TRUE(NotifyWhenFinishedImmediateOneShot("ok - foo result: true"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
-                       CallFinishedAfterSyncUnregistered) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(false);
-  EXPECT_TRUE(RegisterOneShot("foo"));
-  EXPECT_TRUE(StoreRegistrationOneShot("foo"));
-  EXPECT_TRUE(UnregisterOneShot("foo"));
-  EXPECT_FALSE(GetRegistrationOneShot("foo"));
-  EXPECT_TRUE(NotifyWhenFinishedImmediateOneShot("ok - foo result: false"));
-}
-
-IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest, CallFinishedAfterSyncFails) {
-  EXPECT_TRUE(RegisterServiceWorker());
-  EXPECT_TRUE(LoadTestPage(kDefaultTestURL));  // Control the page.
-
-  SetOnline(true);
-  EXPECT_TRUE(RegisterOneShot("delay"));
-  EXPECT_FALSE(OneShotPending("delay"));
-  EXPECT_TRUE(StoreRegistrationOneShot("delay"));
-
-  EXPECT_TRUE(RejectDelayedOneShot());
-  EXPECT_TRUE(PopConsole("ok - delay rejected"));
-  EXPECT_TRUE(NotifyWhenFinishedImmediateOneShot("ok - delay result: false"));
-}
-
 // Verify that a background sync registration is deleted when site data is
 // cleared.
 IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
diff --git a/content/test/data/background_sync/background_sync_test_helpers.js b/content/test/data/background_sync/background_sync_test_helpers.js
index b4cd8b6..7900526 100644
--- a/content/test/data/background_sync/background_sync_test_helpers.js
+++ b/content/test/data/background_sync/background_sync_test_helpers.js
@@ -5,7 +5,6 @@
 'use strict';
 
 var resultQueue = new ResultQueue();
-var registrationReference = null;
 
 // Sends data back to the test. This must be in response to an earlier
 // request, but it's ok to respond asynchronously. The request blocks until
@@ -35,9 +34,9 @@ function registerServiceWorker() {
 function registerOneShot(tag) {
   navigator.serviceWorker.ready
     .then(function(swRegistration) {
-      return swRegistration.sync.register({'tag': tag});
+      return swRegistration.sync.register(tag);
     })
-    .then(function(syncRegistration) {
+    .then(function() {
       sendResultToTest('ok - ' + tag + ' registered');
     })
     .catch(sendErrorToTest);
@@ -52,56 +51,18 @@ function registerOneShotFromServiceWorker(tag) {
     .catch(sendErrorToTest);
 }
 
-function unregisterOneShot(tag) {
-  navigator.serviceWorker.ready
-    .then(function(swRegistration) {
-      return swRegistration.sync.getRegistration(tag);
-    })
-    .then(function(syncRegistration) {
-      if (!syncRegistration) {
-        sendResultToTest('error - ' + tag + ' not found');
-        return;
-      }
-      return syncRegistration.unregister();
-    })
-    .then(function() {
-      sendResultToTest('ok - ' + tag + ' unregistered');
-    })
-    .catch(sendErrorToTest);
-}
-
-function unregisterOneShotTwice(tag) {
-  navigator.serviceWorker.ready
-    .then(function(swRegistration) {
-      return swRegistration.sync.getRegistration(tag);
-    })
-    .then(function(syncRegistration) {
-      if (!syncRegistration) {
-        sendResultToTest('error - ' + tag + ' not found');
-        return;
-      }
-      return syncRegistration.unregister();
-    })
-    .then(function() {
-      return syncRegistration.unregister();
-    })
-    .then(sendErrorToTest, function() {
-      sendResultToTest('ok - ' + tag + ' failed to unregister twice');
-    })
-    .catch(sendErrorToTest);
-}
-
 function getRegistrationOneShot(tag) {
   navigator.serviceWorker.ready
     .then(function(swRegistration) {
-      return swRegistration.sync.getRegistration(tag);
+      return swRegistration.sync.getTags();
     })
-    .then(function(syncRegistration) {
-      if (!syncRegistration) {
+    .then(function(tags) {
+      if (tags.indexOf(tag) >= 0) {
+        sendResultToTest('ok - ' + tag + ' found');
+      } else {
         sendResultToTest('error - ' + tag + ' not found');
         return;
       }
-      sendResultToTest('ok - ' + tag + ' found');
     })
     .catch(sendErrorToTest);
 }
@@ -119,12 +80,9 @@ function getRegistrationOneShotFromServiceWorker(tag) {
 function getRegistrationsOneShot(tag) {
   navigator.serviceWorker.ready
     .then(function(swRegistration) {
-      return swRegistration.sync.getRegistrations();
+      return swRegistration.sync.getTags();
     })
-    .then(function(syncRegistrations) {
-      var tags = syncRegistrations.map(function(syncRegistration) {
-        return syncRegistration.tag;
-      });
+    .then(function(tags) {
       sendResultToTest('ok - ' + tags.toString());
     })
     .catch(sendErrorToTest);
@@ -157,44 +115,6 @@ function rejectDelayedOneShot() {
     .catch(sendErrorToTest);
 }
 
-function notifyWhenFinishedOneShot(tag) {
-  navigator.serviceWorker.ready
-    .then(function(swRegistration) {
-      swRegistration.active.postMessage(
-          {action: 'notifyWhenFinished', tag: tag});
-    })
-    .catch(sendErrorToTest);
-}
-
-function notifyWhenFinishedImmediateOneShot(tag) {
-  if (registrationReference == null) {
-    sendResultToTest('error - must call storeRegistration first');
-    return;
-  }
-
-  registrationReference.finished
-    .then(function(success) {
-      sendResultToTest('ok - ' + registrationReference.tag +
-                       ' result: true')
-    }, function(err) {
-      sendResultToTest('ok - ' + registrationReference.tag +
-                       ' result: false')
-    })
-    .catch(sendErrorToTest)
-}
-
-
-function storeRegistration(tag) {
-  navigator.serviceWorker.ready
-    .then(function(swRegistration) {
-      return swRegistration.sync.getRegistration(tag);
-    })
-    .then(function(syncRegistration) {
-      registrationReference = syncRegistration;
-      sendResultToTest('ok - ' + tag + ' stored');
-    })
-    .catch(sendErrorToTest);
-}
 
 // Queue storing asynchronous results received from the Service Worker. Results
 // are sent to the test when requested.
diff --git a/content/test/data/background_sync/service_worker.js b/content/test/data/background_sync/service_worker.js
index 6fedae8..e04bf30 100644
--- a/content/test/data/background_sync/service_worker.js
+++ b/content/test/data/background_sync/service_worker.js
@@ -9,7 +9,6 @@
 // "delay" - Delays finishing the sync event with event.waitUntil.
 //           Send a postMessage of "completeDelayedOneShot" to finish the
 //           event.
-// "unregister" - Unregisters the sync registration from within the sync event.
 
 'use strict';
 
@@ -38,25 +37,10 @@ this.onmessage = function(event) {
     sendMessageToClients('sync', 'ok - delay rejected');
   }
 
-  if (event.data['action'] === 'notifyWhenFinished') {
-    var tag = event.data['tag'];
-    registration.sync.getRegistration(tag)
-      .then(function (syncRegistration) {
-        sendMessageToClients('sync', 'ok - ' + tag + ' finished');
-        return syncRegistration.finished;
-      })
-      .then(function() {
-        sendMessageToClients('sync', tag + " finished result: true");
-      }, function(error) {
-        sendMessageToClients('sync', tag + " finished result: false");
-      })
-      .catch(sendSyncErrorToClients);
-  }
-
   if (event.data['action'] === 'registerOneShot') {
     var tag = event.data['tag'];
-    registration.sync.register({'tag': tag})
-      .then(function (syncRegistration) {
+    registration.sync.register(tag)
+      .then(function () {
         sendMessageToClients('register', 'ok - ' + tag + ' registered in SW');
       })
       .catch(sendSyncErrorToClients);
@@ -64,23 +48,21 @@ this.onmessage = function(event) {
 
   if (event.data['action'] === 'getRegistrationOneShot') {
     var tag = event.data['tag'];
-    registration.sync.getRegistration(tag)
-      .then(function(syncRegistration) {
-        if (!syncRegistration) {
+    registration.sync.getTags(tag)
+      .then(function(tags) {
+        if (tags.indexOf(tag) >= 0) {
+          sendMessageToClients('register', 'ok - ' + tag + ' found');
+        } else {
           sendMessageToClients('register', 'error - ' + tag + ' not found');
           return;
         }
-        sendMessageToClients('register', 'ok - ' + tag + ' found');
       })
       .catch(sendSyncErrorToClients);
   }
 
   if (event.data['action'] === 'getRegistrationsOneShot') {
-    registration.sync.getRegistrations()
-      .then(function(syncRegistrations) {
-        var tags = syncRegistrations.map(function(syncRegistration) {
-          return syncRegistration.tag;
-        });
+    registration.sync.getTags()
+      .then(function(tags) {
         sendMessageToClients('register', 'ok - ' + tags.toString());
       })
       .catch(sendSyncErrorToClients);
@@ -103,17 +85,12 @@ this.onsync = function(event) {
     sendMessageToClients('sync', 'error - wrong wait until type');
   }
 
-  if (event.registration === undefined) {
-    sendMessageToClients('sync', 'error - event missing registration');
-    return;
-  }
-
-  if (event.registration.tag === undefined) {
+  if (event.tag === undefined) {
     sendMessageToClients('sync', 'error - registration missing tag');
     return;
   }
 
-  var tag = event.registration.tag;
+  var tag = event.tag;
 
   if (tag === 'delay') {
     var syncPromise = new Promise(function(resolve, reject) {
@@ -124,14 +101,6 @@ this.onsync = function(event) {
     return;
   }
 
-  if (tag === 'unregister') {
-    event.waitUntil(event.registration.unregister()
-      .then(function() {
-        sendMessageToClients('sync', 'ok - unregister completed');
-      }));
-    return;
-  }
-
   sendMessageToClients('sync', tag + ' fired');
 };
 
diff --git a/third_party/WebKit/LayoutTests/http/tests/background_sync/interfaces.html b/third_party/WebKit/LayoutTests/http/tests/background_sync/interfaces.html
index c5d4e1b2..d183f40 100644
--- a/third_party/WebKit/LayoutTests/http/tests/background_sync/interfaces.html
+++ b/third_party/WebKit/LayoutTests/http/tests/background_sync/interfaces.html
@@ -18,23 +18,9 @@
           assert_own_property(self, 'SyncManager', 'SyncManager needs to be exposed as a global.');
 
           assert_own_property(SyncManager.prototype, 'register');
-          assert_own_property(SyncManager.prototype, 'getRegistration');
-          assert_own_property(SyncManager.prototype, 'getRegistrations');
-          assert_own_property(SyncManager.prototype, 'permissionState');
+          assert_own_property(SyncManager.prototype, 'getTags');
 
       }, 'SyncManager should be exposed and have the expected interface in a Document.');
-
-      test(function() {
-          assert_own_property(self, 'SyncRegistration', 'SyncRegistration needs to be exposed as a global.');
-
-          // FIXME: Assert existence of the attributes when they are properly
-          // exposed in the prototype chain. https://crbug.com/43394
-
-          assert_own_property(SyncRegistration.prototype, 'finished');
-          assert_own_property(SyncRegistration.prototype, 'unregister');
-          assert_own_property(SyncRegistration.prototype, 'tag');
-
-      }, 'SyncRegistration should be exposed and have the expected interface in a Document.');
     </script>
   </body>
 </html>
diff --git a/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot-register-failure-worker-not-activated.html b/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot-register-failure-worker-not-activated.html
index 7768008..9b35a5e 100644
--- a/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot-register-failure-worker-not-activated.html
+++ b/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot-register-failure-worker-not-activated.html
@@ -17,7 +17,7 @@ async_test(function(test) {
             swRegistration = serviceWorkerRegistration;
             assert_not_equals(swRegistration.installing, null, 'The worker should be installing');
             assert_equals(swRegistration.active, null, 'The worker should not be active yet');
-            return swRegistration.sync.register();
+            return swRegistration.sync.register('abcde');
         })
         .then(function(syncRegistration) {
             assert_unreached('sync.register() must not succeed without an active service worker');
diff --git a/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot.html b/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot.html
index 87663fa..e2090b9 100644
--- a/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot.html
+++ b/third_party/WebKit/LayoutTests/http/tests/background_sync/oneshot.html
@@ -6,7 +6,6 @@
 <script src="../resources/testharness-helpers.js"></script>
 <script src="../resources/testharnessreport.js"></script>
 <script src="../serviceworker/resources/test-helpers.js"></script>
-<script src="resources/test-helpers.js"></script>
 <script>
 
 promise_test(function(t) {
@@ -15,9 +14,9 @@ promise_test(function(t) {
   var sync_manager;
   var sync_registration;
 
-  // One-shot syncs can only be registered from a controlled document. This
-  // test creates a frame, after the service worker is active, in order to use
-  // its service worker registration.
+  // This test verifies that one-shot syncs can be registered from service-
+  // worker-controlled documents. It creates a frame, after the service worker
+  // is active, in order to use its service worker registration.
   return service_worker_unregister_and_register(t, url, scope)
     .then(function(sw_registration_page) {
         return wait_for_state(t, sw_registration_page.installing, 'activated');
@@ -31,21 +30,14 @@ promise_test(function(t) {
       })
     .then(function(sw_registration_frame) {
         sync_manager = sw_registration_frame.sync;
-        return clear_registered_syncs(sync_manager);
+        return sync_manager.getTags();
       })
-    .then(function() { return sync_manager.getRegistrations(); })
-    .then(function(registrations) {
-        assert_equals(registrations.length, 0, 'One-shot syncs should be ' +
+    .then(function(tags) {
+        assert_equals(tags.length, 0, 'One-shot syncs should be ' +
                       'cleared at the start of the test.');
-        return sync_manager.register({tag: 'abcde'});
+        return sync_manager.register('abcde');
       })
-    .then(function(registration) {
-        sync_registration = registration;
-        assert_class_string(sync_registration, 'SyncRegistration', 'One-' +
-                            'shot sync registrations should have the correct ' +
-                            'class name.');
-        assert_equals('abcde', registration.tag, 'Sync registration tag ' +
-                      'returned should match the tag registered.');
+    .then(function() {
         return service_worker_unregister(t, scope);
       });
   }, 'Background Sync API should allow one-shot syncs to be registered from ' +
@@ -57,31 +49,22 @@ promise_test(function(t) {
   var sync_manager;
   var sync_registration;
 
-  // One-shot syncs can also be registered from uncontrolled documents. This
-  // test creates a frame, after the service worker is active, in order to use
-  // its service worker registration.
+  // This test verifies that one-shot syncs can be registered from uncontrolled
+  // documents.
   return service_worker_unregister_and_register(t, url, scope)
     .then(function(sw_registration) {
         sync_manager = sw_registration.sync;
         return wait_for_state(t, sw_registration.installing, 'activated');
       })
-    .then(function() { return clear_registered_syncs(sync_manager); })
-    .then(function() { return sync_manager.getRegistrations(); })
-    .then(function(registrations) {
-        assert_equals(registrations.length, 0, 'One-shot syncs should be ' +
+    .then(function() { return sync_manager.getTags(); })
+    .then(function(tags) {
+        assert_equals(tags.length, 0, 'One-shot syncs should be ' +
                       'cleared at the start of the test.');
-        return sync_manager.register({tag: 'abcde'});
+        return sync_manager.register('abcde');
       })
-    .then(function(registration) {
-        sync_registration = registration;
-        assert_class_string(sync_registration, 'SyncRegistration', 'One-' +
-                            'shot sync registrations should have the correct ' +
-                            'class name.');
-        assert_equals('abcde', registration.tag, 'Sync registration tag ' +
-                      'returned should match the tag registered.');
+    .then(function() {
         return service_worker_unregister(t, scope);
       })
-    .then(function() { return service_worker_unregister(t, scope); })
   }, 'Background Sync API should allow one-shot syncs to be registered ' +
      'with window clients not currently controlled by service worker');
 </script>
diff --git a/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/interfaces-worker.js b/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/interfaces-worker.js
index c638025..0df2dca 100644
--- a/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/interfaces-worker.js
+++ b/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/interfaces-worker.js
@@ -6,27 +6,14 @@ test(function() {
     assert_idl_attribute(registration, 'sync', 'One-shot SyncManager needs to be exposed on the registration.');
 
     assert_inherits(registration.sync, 'register');
-    assert_inherits(registration.sync, 'getRegistration');
-    assert_inherits(registration.sync, 'getRegistrations');
-    assert_inherits(registration.sync, 'permissionState');
+    assert_inherits(registration.sync, 'getTags');
 
 }, 'SyncManager should be exposed and have the expected interface.');
 
 test(function() {
-    assert_own_property(self, 'SyncRegistration', 'SyncRegistration needs to be exposed as a global.');
-
-    // FIXME: Assert existence of the attributes when they are properly
-    // exposed in the prototype chain. https://crbug.com/43394
-    assert_own_property(SyncRegistration.prototype, 'finished');
-    assert_own_property(SyncRegistration.prototype, 'unregister');
-    assert_own_property(SyncRegistration.prototype, 'tag');
-
-}, 'SyncRegistration should be exposed and have the expected interface.');
-
-test(function() {
     assert_own_property(self, 'SyncEvent');
 
-    assert_will_be_idl_attribute(SyncEvent.prototype, 'registration');
+    assert_will_be_idl_attribute(SyncEvent.prototype, 'tag');
 
     // SyncEvent should be extending ExtendableEvent.
     assert_inherits(SyncEvent.prototype, 'waitUntil');
diff --git a/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/test-helpers.js b/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/test-helpers.js
deleted file mode 100644
index da0b7e9..0000000
--- a/third_party/WebKit/LayoutTests/http/tests/background_sync/resources/test-helpers.js
+++ /dev/null
@@ -1,13 +0,0 @@
-// Returns a promise which resolves when all registrations have been cleared
-// from the given background sync manager.
-function clear_registered_syncs(sync_manager) {
-  return sync_manager.getRegistrations().then(function(registrations) {
-    return Promise.all(
-      registrations.map(registration => registration.unregister()));
-  });
-}
-
-// Clears all background sync registrations from the sync manager.
-function clear_all_syncs(serviceworker_registration) {
-  return clear_registered_syncs(serviceworker_registration.sync);
-}
diff --git a/third_party/WebKit/LayoutTests/http/tests/serviceworker/webexposed/global-interface-listing-service-worker-expected.txt b/third_party/WebKit/LayoutTests/http/tests/serviceworker/webexposed/global-interface-listing-service-worker-expected.txt
index bf66956..f6ff90d 100644
--- a/third_party/WebKit/LayoutTests/http/tests/serviceworker/webexposed/global-interface-listing-service-worker-expected.txt
+++ b/third_party/WebKit/LayoutTests/http/tests/serviceworker/webexposed/global-interface-listing-service-worker-expected.txt
@@ -587,19 +587,12 @@ interface SubtleCrypto
     method wrapKey
 interface SyncEvent : ExtendableEvent
     getter lastChance
-    getter registration
+    getter tag
     method constructor
 interface SyncManager
     method constructor
-    method getRegistration
-    method getRegistrations
-    method permissionState
+    method getTags
     method register
-interface SyncRegistration
-    getter finished
-    getter tag
-    method constructor
-    method unregister
 interface TextDecoder
     getter encoding
     getter fatal
diff --git a/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt b/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
index f468c4a..1f0a02b 100644
--- a/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
+++ b/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
@@ -5160,15 +5160,8 @@ interface SubtleCrypto
     method wrapKey
 interface SyncManager
     method constructor
-    method getRegistration
-    method getRegistrations
-    method permissionState
+    method getTags
     method register
-interface SyncRegistration
-    getter finished
-    getter tag
-    method constructor
-    method unregister
 interface Text : CharacterData
     getter wholeText
     method constructor
diff --git a/third_party/WebKit/Source/core/frame/UseCounter.h b/third_party/WebKit/Source/core/frame/UseCounter.h
index afc2599..895bda7 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.h
+++ b/third_party/WebKit/Source/core/frame/UseCounter.h
@@ -884,6 +884,7 @@ public:
         CSSFilterContrast = 1022,
         CSSFilterBlur = 1023,
         CSSFilterDropShadow = 1024,
+        BackgroundSyncRegister = 1025,
 
         // Add new features immediately above this line. Don't change assigned
         // numbers of any item, and don't reuse removed slots.
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp b/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
index c0cd78e..9f31ab1 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
+++ b/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
@@ -120,20 +120,14 @@ SyncGetRegistrationsCallbacks::~SyncGetRegistrationsCallbacks()
 
 void SyncGetRegistrationsCallbacks::onSuccess(const WebVector<WebSyncRegistration*>& webSyncRegistrations)
 {
-    Vector<OwnPtr<WebSyncRegistration>> registrations;
-    for (WebSyncRegistration* r : webSyncRegistrations) {
-        registrations.append(adoptPtr(r));
-    }
     if (!m_resolver->executionContext() || m_resolver->executionContext()->activeDOMObjectsAreStopped()) {
         return;
     }
-
-    HeapVector<Member<SyncRegistration>> syncRegistrations;
-    for (auto& r : registrations) {
-        SyncRegistration* reg = SyncRegistration::take(m_resolver.get(), r.release(), m_serviceWorkerRegistration);
-        syncRegistrations.append(reg);
+    Vector<String> tags;
+    for (const WebSyncRegistration* r : webSyncRegistrations) {
+        tags.append(r->tag);
     }
-    m_resolver->resolve(syncRegistrations);
+    m_resolver->resolve(tags);
 }
 
 void SyncGetRegistrationsCallbacks::onError(const WebSyncError& error)
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncEvent.cpp b/third_party/WebKit/Source/modules/background_sync/SyncEvent.cpp
index b109a11..c4f7906 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncEvent.cpp
+++ b/third_party/WebKit/Source/modules/background_sync/SyncEvent.cpp
@@ -11,9 +11,9 @@ SyncEvent::SyncEvent()
 {
 }
 
-SyncEvent::SyncEvent(const AtomicString& type, SyncRegistration* syncRegistration, bool lastChance, WaitUntilObserver* observer)
+SyncEvent::SyncEvent(const AtomicString& type, const String& tag, bool lastChance, WaitUntilObserver* observer)
     : ExtendableEvent(type, ExtendableEventInit(), observer)
-    , m_syncRegistration(syncRegistration)
+    , m_tag(tag)
     , m_lastChance(lastChance)
 {
 }
@@ -21,7 +21,7 @@ SyncEvent::SyncEvent(const AtomicString& type, SyncRegistration* syncRegistratio
 SyncEvent::SyncEvent(const AtomicString& type, const SyncEventInit& init)
     : ExtendableEvent(type, init)
 {
-    m_syncRegistration = init.registration();
+    m_tag = init.tag();
     m_lastChance = init.lastChance();
 }
 
@@ -34,9 +34,9 @@ const AtomicString& SyncEvent::interfaceName() const
     return EventNames::SyncEvent;
 }
 
-SyncRegistration* SyncEvent::registration()
+String SyncEvent::tag()
 {
-    return m_syncRegistration.get();
+    return m_tag;
 }
 
 bool SyncEvent::lastChance()
@@ -46,7 +46,6 @@ bool SyncEvent::lastChance()
 
 DEFINE_TRACE(SyncEvent)
 {
-    visitor->trace(m_syncRegistration);
     ExtendableEvent::trace(visitor);
 }
 
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncEvent.h b/third_party/WebKit/Source/modules/background_sync/SyncEvent.h
index d5b8665..5b969a5 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncEvent.h
+++ b/third_party/WebKit/Source/modules/background_sync/SyncEvent.h
@@ -22,9 +22,9 @@ public:
     {
         return adoptRefWillBeNoop(new SyncEvent);
     }
-    static PassRefPtrWillBeRawPtr<SyncEvent> create(const AtomicString& type, SyncRegistration* syncRegistration, bool lastChance, WaitUntilObserver* observer)
+    static PassRefPtrWillBeRawPtr<SyncEvent> create(const AtomicString& type, const String& tag, bool lastChance, WaitUntilObserver* observer)
     {
-        return adoptRefWillBeNoop(new SyncEvent(type, syncRegistration, lastChance, observer));
+        return adoptRefWillBeNoop(new SyncEvent(type, tag, lastChance, observer));
     }
     static PassRefPtrWillBeRawPtr<SyncEvent> create(const AtomicString& type, const SyncEventInit& init)
     {
@@ -35,17 +35,17 @@ public:
 
     const AtomicString& interfaceName() const override;
 
-    SyncRegistration* registration();
+    String tag();
     bool lastChance();
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     SyncEvent();
-    SyncEvent(const AtomicString& type, SyncRegistration*, bool, WaitUntilObserver*);
+    SyncEvent(const AtomicString& type, const String&, bool, WaitUntilObserver*);
     SyncEvent(const AtomicString& type, const SyncEventInit&);
 
-    PersistentWillBeMember<SyncRegistration> m_syncRegistration;
+    String m_tag;
     bool m_lastChance;
 };
 
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncEvent.idl b/third_party/WebKit/Source/modules/background_sync/SyncEvent.idl
index f828e49..f663de05 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncEvent.idl
+++ b/third_party/WebKit/Source/modules/background_sync/SyncEvent.idl
@@ -7,6 +7,6 @@
     Exposed=ServiceWorker,
     RuntimeEnabled=BackgroundSync,
 ] interface SyncEvent : ExtendableEvent {
-    readonly attribute SyncRegistration registration;
+    readonly attribute DOMString tag;
     readonly attribute boolean lastChance;
 };
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncEventInit.idl b/third_party/WebKit/Source/modules/background_sync/SyncEventInit.idl
index df44f64..1a2a804 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncEventInit.idl
+++ b/third_party/WebKit/Source/modules/background_sync/SyncEventInit.idl
@@ -3,6 +3,6 @@
 // found in the LICENSE file.
 
 dictionary SyncEventInit : ExtendableEventInit {
-    required SyncRegistration registration;
-    required boolean lastChance;
+    required DOMString tag;
+    boolean lastChance = false;
 };
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncManager.cpp b/third_party/WebKit/Source/modules/background_sync/SyncManager.cpp
index dae56c1ee..4593672 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncManager.cpp
+++ b/third_party/WebKit/Source/modules/background_sync/SyncManager.cpp
@@ -40,7 +40,7 @@ SyncManager::SyncManager(ServiceWorkerRegistration* registration)
     ASSERT(registration);
 }
 
-ScriptPromise SyncManager::registerFunction(ScriptState* scriptState, ExecutionContext* context, const SyncRegistrationOptions& options)
+ScriptPromise SyncManager::registerFunction(ScriptState* scriptState, ExecutionContext* context, const String& tag)
 {
     // TODO(jkarlin): Wait for the registration to become active instead of rejecting. See crbug.com/542437.
     if (!m_registration->active())
@@ -52,7 +52,7 @@ ScriptPromise SyncManager::registerFunction(ScriptState* scriptState, ExecutionC
     WebSyncRegistration* webSyncRegistration = new WebSyncRegistration(
         WebSyncRegistration::UNREGISTERED_SYNC_ID /* id */,
         WebSyncRegistration::PeriodicityOneShot,
-        options.tag(),
+        tag,
         0 /* minPeriod */,
         WebSyncRegistration::NetworkStateOnline /* networkState */,
         WebSyncRegistration::PowerStateAuto /* powerState */
@@ -62,17 +62,7 @@ ScriptPromise SyncManager::registerFunction(ScriptState* scriptState, ExecutionC
     return promise;
 }
 
-ScriptPromise SyncManager::getRegistration(ScriptState* scriptState, const String& syncRegistrationId)
-{
-    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
-    ScriptPromise promise = resolver->promise();
-
-    backgroundSyncProvider()->getRegistration(WebSyncRegistration::PeriodicityOneShot, syncRegistrationId, m_registration->webRegistration(), new SyncRegistrationCallbacks(resolver, m_registration));
-
-    return promise;
-}
-
-ScriptPromise SyncManager::getRegistrations(ScriptState* scriptState)
+ScriptPromise SyncManager::getTags(ScriptState* scriptState)
 {
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
@@ -82,16 +72,6 @@ ScriptPromise SyncManager::getRegistrations(ScriptState* scriptState)
     return promise;
 }
 
-ScriptPromise SyncManager::permissionState(ScriptState* scriptState)
-{
-    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
-    ScriptPromise promise = resolver->promise();
-
-    backgroundSyncProvider()->getPermissionStatus(WebSyncRegistration::PeriodicityOneShot, m_registration->webRegistration(), new SyncGetPermissionStatusCallbacks(resolver, m_registration));
-
-    return promise;
-}
-
 DEFINE_TRACE(SyncManager)
 {
     visitor->trace(m_registration);
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncManager.h b/third_party/WebKit/Source/modules/background_sync/SyncManager.h
index 8690788..2529574 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncManager.h
+++ b/third_party/WebKit/Source/modules/background_sync/SyncManager.h
@@ -27,10 +27,8 @@ public:
 
     unsigned long minAllowablePeriod();
 
-    ScriptPromise registerFunction(ScriptState*, ExecutionContext*, const SyncRegistrationOptions&);
-    ScriptPromise getRegistration(ScriptState*, const String&);
-    ScriptPromise getRegistrations(ScriptState*);
-    ScriptPromise permissionState(ScriptState*);
+    ScriptPromise registerFunction(ScriptState*, ExecutionContext*, const String&);
+    ScriptPromise getTags(ScriptState*);
 
     DECLARE_TRACE();
 
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncManager.idl b/third_party/WebKit/Source/modules/background_sync/SyncManager.idl
index 30f3ada..de186a1 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncManager.idl
+++ b/third_party/WebKit/Source/modules/background_sync/SyncManager.idl
@@ -14,8 +14,6 @@ enum SyncPermissionState {
     RuntimeEnabled=BackgroundSync,
     TypeChecking=Interface,
 ] interface SyncManager {
-    [CallWith=(ScriptState,ExecutionContext),ImplementedAs=registerFunction] Promise<SyncRegistration> register([RuntimeEnabled=BackgroundSyncV2] optional SyncRegistrationOptions options);
-    [CallWith=ScriptState] Promise<SyncRegistration> getRegistration(DOMString tag);
-    [CallWith=ScriptState] Promise<sequence<SyncRegistration>> getRegistrations();
-    [RuntimeEnabled=BackgroundSyncV2, CallWith=ScriptState] Promise<SyncPermissionState> permissionState();
+    [MeasureAs=BackgroundSyncRegister,CallWith=(ScriptState,ExecutionContext),ImplementedAs=registerFunction] Promise<void> register(DOMString tag);
+    [CallWith=ScriptState] Promise<sequence<DOMString>> getTags();
 };
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncRegistration.idl b/third_party/WebKit/Source/modules/background_sync/SyncRegistration.idl
index add356e..ccc69db 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncRegistration.idl
+++ b/third_party/WebKit/Source/modules/background_sync/SyncRegistration.idl
@@ -3,8 +3,8 @@
 // found in the LICENSE file.
 
 [
-    Exposed=(Window,ServiceWorker),
     GarbageCollected,
+    NoInterfaceObject,
     RuntimeEnabled=BackgroundSync,
 ] interface SyncRegistration {
     readonly attribute DOMString tag;
diff --git a/third_party/WebKit/Source/web/ServiceWorkerGlobalScopeProxy.cpp b/third_party/WebKit/Source/web/ServiceWorkerGlobalScopeProxy.cpp
index 3a311b1..fbf8875 100644
--- a/third_party/WebKit/Source/web/ServiceWorkerGlobalScopeProxy.cpp
+++ b/third_party/WebKit/Source/web/ServiceWorkerGlobalScopeProxy.cpp
@@ -61,6 +61,7 @@
 #include "modules/serviceworkers/WaitUntilObserver.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/WebCrossOriginServiceWorkerClient.h"
+#include "public/platform/modules/background_sync/WebSyncRegistration.h"
 #include "public/platform/modules/notifications/WebNotificationData.h"
 #include "public/platform/modules/serviceworker/WebServiceWorkerEventResult.h"
 #include "public/platform/modules/serviceworker/WebServiceWorkerRequest.h"
@@ -177,7 +178,7 @@ void ServiceWorkerGlobalScopeProxy::dispatchSyncEvent(int eventID, const WebSync
         return;
     }
     WaitUntilObserver* observer = WaitUntilObserver::create(m_workerGlobalScope, WaitUntilObserver::Sync, eventID);
-    RefPtrWillBeRawPtr<Event> event(SyncEvent::create(EventTypeNames::sync, SyncRegistration::create(registration, m_workerGlobalScope->registration()), lastChance == IsLastChance, observer));
+    RefPtrWillBeRawPtr<Event> event(SyncEvent::create(EventTypeNames::sync, registration.tag, lastChance == IsLastChance, observer));
     m_workerGlobalScope->dispatchExtendableEvent(event.release(), observer);
 }