Move content/child/background_sync to Blink.

third_party/WebKit/Source/modules/background_sync/SyncManager.h

Index: third_party/WebKit/Source/modules/background_sync/SyncManager.h
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncManager.h b/third_party/WebKit/Source/modules/background_sync/SyncManager.h
index aba3118bc638329cbc1e426e72e756050810413a..ebb85b437a897fc3ceafd0b63c2d475d61c9e88b 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncManager.h
+++ b/third_party/WebKit/Source/modules/background_sync/SyncManager.h
@@ -6,6 +6,7 @@
 #define SyncManager_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
+#include "modules/background_sync/BackgroundSyncProvider.h"

[jbroman, 2016/11/07 19:48:10]

super-nit: if you only need to refer to the pointer (like here), you can use a
forward-declaration instead of a #include (and put the #include in the source
file) to save compile time.

[adithyas, 2016/11/08 16:47:47]

Done.

 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
@@ -32,9 +33,13 @@ class SyncManager final : public GarbageCollected<SyncManager>,
 
   DECLARE_TRACE();
 
+  enum { kUnregisteredSyncID = -1 };
+
  private:
   explicit SyncManager(ServiceWorkerRegistration*);
 
+  static BackgroundSyncProvider* backgroundSyncProvider();
+
   Member<ServiceWorkerRegistration> m_registration;
 };