[Offline Pages] Turn Offliner::Cancel into an async operation to resolve conflicting assumptions

components/offline_pages/core/background/offliner_stub.cc

Index: components/offline_pages/core/background/offliner_stub.cc
diff --git a/components/offline_pages/core/background/offliner_stub.cc b/components/offline_pages/core/background/offliner_stub.cc
index 0455fe08d7155575ba2d3d8eb96aa38c41658371..9ffd59c62df4bf1f2b7fa6609f75a9f82956d45d 100644
--- a/components/offline_pages/core/background/offliner_stub.cc
+++ b/components/offline_pages/core/background/offliner_stub.cc
@@ -31,8 +31,9 @@ bool OfflinerStub::LoadAndSave(const SavePageRequest& request,
   return true;
 }
 
-void OfflinerStub::Cancel() {
+void OfflinerStub::Cancel(const CancelCallback& callback) {
   cancel_called_ = true;
+  callback.Run(0L);

[fgorski, 2017/02/27 18:07:25]

0LL?

[chili, 2017/02/28 00:44:14]

Done.

 }
 
 }  // namespace offline_pages