Move content/child/background_sync to Blink.

third_party/WebKit/Source/modules/background_sync/SyncManager.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 SyncManager_h
 #define SyncManager_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
+#include "modules/background_sync/BackgroundSyncProvider.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class ExecutionContext;
 class ScriptPromise;
 class ScriptState;
 class ServiceWorkerRegistration;
 
 class SyncManager final : public GarbageCollected<SyncManager>,
                           public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   static SyncManager* create(ServiceWorkerRegistration* registration) {
     return new SyncManager(registration);
   }
 
   ScriptPromise registerFunction(ScriptState*,
                                  ExecutionContext*,
                                  const String&);
   ScriptPromise getTags(ScriptState*);
 
   DECLARE_TRACE();
 
+  enum { UNREGISTERED_SYNC_ID = -1 };

[jbroman, 2016/11/05 22:51:09]

nit: kUnregisteredSyncID (Blink name conventions)

[adithyas, 2016/11/07 19:22:56]

Done.

+
  private:
   explicit SyncManager(ServiceWorkerRegistration*);
 
+  static BackgroundSyncProvider* backgroundSyncProvider();
+
   Member<ServiceWorkerRegistration> m_registration;
 };
 
 }  // namespace blink
 
 #endif  // SyncManager_h