Clean up WebSyncProvider now that the browser has implemented the necessary functionality.

public/platform/modules/background_sync/WebSyncProvider.h

 // Copyright 2015 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 WebSyncProvider_h
 #define WebSyncProvider_h
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebCommon.h"
 #include "public/platform/WebPassOwnPtr.h"
@@ skipping 30 matching lines @@
 
     // Takes ownership of the WebSyncGetRegistrationsCallbacks.
     // Does not take ownership of the WebServiceWorkerRegistration.
     virtual void getRegistrations(blink::WebSyncRegistration::Periodicity, WebServiceWorkerRegistration*, WebSyncGetRegistrationsCallbacks*) = 0;
 
     // Takes ownership of the WebSyncGetPermissionStatusCallbacks.
     // Does not take ownership of the WebServiceWorkerRegistration.
     virtual void getPermissionStatus(blink::WebSyncRegistration::Periodicity, WebServiceWorkerRegistration*, WebSyncGetPermissionStatusCallbacks*) = 0;
 
     // Takes ownership of the WebSyncNotifyWhenDoneCallbacks.
-    virtual void notifyWhenDone(int64_t syncId, WebSyncNotifyWhenDoneCallbacks* callbacks)
-    {
-        // TODO(jkarlin): After landing both legs of the notifyWhenDone CLs, make this a pure virtual function.
-        callbacks->onError(WebSyncError(WebSyncError::ErrorTypeAbort, "Function not implemented."));
-        delete callbacks;
-    }
+    virtual void notifyWhenDone(int64_t syncId, WebSyncNotifyWhenDoneCallbacks*) = 0;
 
-    // Takes ownership of the WebServiceWorkerRegistration.
-    virtual void trackRegistration(WebSyncRegistration* registration)
-    {
-        // TODO(jkarlin): After landing both legs of the releaseRegistration CLs, make this a pure virtual function.
-        return;
-    }
-
-    virtual void releaseRegistration(int64_t syncId)
-    {
-        // TODO(jkarlin): After landing both legs of the releaseRegistration CLs, make this a pure virtual function.
-        return;
-    }
+    virtual void releaseRegistration(int64_t syncId) = 0;
 };
 
 } // namespace blink
 
 #endif // WebSyncProvider_h