Use std::unique_ptr for access to BackgroundFetchJobInfo

content/browser/background_fetch/background_fetch_data_manager.h

Index: content/browser/background_fetch/background_fetch_data_manager.h
diff --git a/content/browser/background_fetch/background_fetch_data_manager.h b/content/browser/background_fetch/background_fetch_data_manager.h
index 9261abea1bb7ec39142e46471edf031505749591..72d15ee77be42082b5d0e2be83621a14a2bb7ebc 100644
--- a/content/browser/background_fetch/background_fetch_data_manager.h
+++ b/content/browser/background_fetch/background_fetch_data_manager.h
@@ -32,11 +32,11 @@ class CONTENT_EXPORT BackgroundFetchDataManager {
   // Called by BackgroundFetchContext when a new request is started, this will
   // store all of the necessary metadata to track the request.
   std::unique_ptr<BackgroundFetchJobData> CreateRequest(
-      const BackgroundFetchJobInfo& job_info,
+      std::unique_ptr<BackgroundFetchJobInfo> job_info,
       BackgroundFetchRequestInfos request_infos);
 
  private:
-  void WriteJobToStorage(const BackgroundFetchJobInfo& job_info,
+  void WriteJobToStorage(std::unique_ptr<BackgroundFetchJobInfo> job_info,

[Peter Beverloo, 2017/03/20 18:14:05]

This confuses me. There's only one call-site now, but we're limiting ourselves
by having only a single call-site by having methods like this take a
std::unique_ptr<> too. What if we have to write to storage later on, e.g.
because the job has to be updated?

[harkness, 2017/03/20 18:40:26]

I was thinking we were going to move to a world where once the JobInfo was
written to storage, we weren't going to keep any reference to it, in which case
we'd want the lifetime of the in memory version to be tied to when it gets
written out. That's why I was passing ownership here.

[Peter Beverloo, 2017/03/20 18:42:41]

OK.

                          BackgroundFetchRequestInfos request_infos);
 
   BackgroundFetchRequestInfos& ReadRequestsFromStorage(
@@ -52,7 +52,8 @@ class CONTENT_EXPORT BackgroundFetchDataManager {
 
   // Temporary map to hold data which will be written to storage.
   // Map from job_guid to JobInfo.
-  std::unordered_map<std::string, BackgroundFetchJobInfo> job_map_;
+  std::unordered_map<std::string, std::unique_ptr<BackgroundFetchJobInfo>>
+      job_map_;
   // Map from job_guid to RequestInfos.
   std::unordered_map<std::string, BackgroundFetchRequestInfos> request_map_;