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

chrome/browser/android/offline_pages/prerendering_offliner.cc

Index: chrome/browser/android/offline_pages/prerendering_offliner.cc
diff --git a/chrome/browser/android/offline_pages/prerendering_offliner.cc b/chrome/browser/android/offline_pages/prerendering_offliner.cc
index 31c0813bdb86721bd1922114781bf64ee9d8547a..91ed919f1a3aa0a1acdc54ef4075a0d2a91c48d3 100644
--- a/chrome/browser/android/offline_pages/prerendering_offliner.cc
+++ b/chrome/browser/android/offline_pages/prerendering_offliner.cc
@@ -191,13 +191,16 @@ bool PrerenderingOffliner::LoadAndSave(const SavePageRequest& request,
   return accepted;
 }
 
-void PrerenderingOffliner::Cancel() {
+void PrerenderingOffliner::Cancel(const CancelCallback& callback) {
+  int64_t request_id = 0L;

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

0LL?

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

Done.

   if (pending_request_) {
+    request_id = pending_request_->request_id();
     pending_request_.reset(nullptr);
     app_listener_.reset(nullptr);
     GetOrCreateLoader()->StopLoading();
     // TODO(dougarnett): Consider ability to cancel SavePage request.
   }
+  callback.Run(request_id);
 }
 
 void PrerenderingOffliner::SetLoaderForTesting(
@@ -238,10 +241,14 @@ void PrerenderingOffliner::OnApplicationStateChange(
           base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES) {
     DVLOG(1) << "App became active, canceling current offlining request";
     SavePageRequest* request = pending_request_.get();
-    Cancel();
-    completion_callback_.Run(*request,
-                             Offliner::RequestStatus::FOREGROUND_CANCELED);
+    Cancel(base::Bind(&PrerenderingOffliner::HandleApplicationStateChangeCancel,

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

add the same comment as before please.

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

Done.

+                      weak_ptr_factory_.GetWeakPtr(), *request));
   }
 }
 
+void PrerenderingOffliner::HandleApplicationStateChangeCancel(
+    const SavePageRequest& request,
+    int64_t offline_id) {
+  completion_callback_.Run(request, RequestStatus::FOREGROUND_CANCELED);
+}
 }  // namespace offline_pages