Connect BackgroundFetch to the OfflineItemCollection

content/browser/background_fetch/background_fetch_registration_id.h

Index: content/browser/background_fetch/background_fetch_registration_id.h
diff --git a/content/browser/background_fetch/background_fetch_registration_id.h b/content/browser/background_fetch/background_fetch_registration_id.h
index 32fb5da8145ae94420d4c4c0c74085ddeeb09f5c..286b7ab948e9acc970a267bdf674b2cada31662c 100644
--- a/content/browser/background_fetch/background_fetch_registration_id.h
+++ b/content/browser/background_fetch/background_fetch_registration_id.h
@@ -39,6 +39,15 @@ class CONTENT_EXPORT BackgroundFetchRegistrationId {
   // Returns whether this registration id refers to valid data.
   bool is_null() const;
 
+  // Serialize the registration_id into a string so that it can be sent to
+  // embedders in a neutral format. Syntax is:
+  // service_worker_registration_id:origin:tag

[Peter Beverloo, 2017/03/31 01:32:23]

I personally wouldn't document the syntax of the serialized format in the header
file. Since we provide both Serialize and Deserialize methods, the contract can
be that code dealing with a serialized_registration_id should treat it as an
opaque identifier.

[harkness, 2017/03/31 10:11:44]

OK, I've moved the documentation to the .cc file.

+  std::string Serialize() const;
+
+  // Deserialize the string format of a registration_id.
+  static bool Deserialize(const std::string& serialized_registration_id,
+                          BackgroundFetchRegistrationId& out_registration_id);

[Peter Beverloo, 2017/03/31 01:32:23]

micro nit: style guide says static methods should go on top. My personal
preference still is for the reference to become a pointer, because it's much
clearer at call-site that the BFRegId is being written to.

[harkness, 2017/03/31 10:11:44]

Done.

+
   int64_t service_worker_registration_id() const {
     return service_worker_registration_id_;
   }