Reporting: Implement serializer.

net/reporting/reporting_context.h

Index: net/reporting/reporting_context.h
diff --git a/net/reporting/reporting_context.h b/net/reporting/reporting_context.h
index c4360ea51e06801a30563788bd69ce958010229b..75aa11918ae6aeff76c20b59a146ca6ee1a2e10d 100644
--- a/net/reporting/reporting_context.h
+++ b/net/reporting/reporting_context.h
@@ -26,6 +26,7 @@ class ReportingDeliveryAgent;
 class ReportingEndpointManager;
 class ReportingGarbageCollector;
 class ReportingObserver;
+class ReportingPersister;
 class ReportingUploader;
 class URLRequestContext;
 
@@ -40,6 +41,16 @@ class NET_EXPORT ReportingContext {
 
   ~ReportingContext();
 
+  // Initializes the ReportingContext. This may take a while (e.g. it may
+  // involve reloading state persisted to disk). Should be called only once.
+  //
+  // Components of the ReportingContext won't reference their dependencies (e.g.
+  // the Clock/TickClock or Timers inside the individual components) until
+  // during/after the call to Init.
+  void Initialize();
+
+  bool initialized() const { return initialized_; }
+
   const ReportingPolicy& policy() { return policy_; }
   ReportingDelegate* delegate() { return delegate_.get(); }
 
@@ -56,6 +67,8 @@ class NET_EXPORT ReportingContext {
     return garbage_collector_.get();
   }
 
+  ReportingPersister* persister() { return persister_.get(); }
+
   void AddObserver(ReportingObserver* observer);
   void RemoveObserver(ReportingObserver* observer);
 
@@ -77,6 +90,7 @@ class NET_EXPORT ReportingContext {
   std::unique_ptr<ReportingUploader> uploader_;
 
   base::ObserverList<ReportingObserver, /* check_empty= */ true> observers_;
+  bool initialized_;
 
   std::unique_ptr<ReportingCache> cache_;
 
@@ -87,6 +101,10 @@ class NET_EXPORT ReportingContext {
   // and |endpoint_manager_|.
   std::unique_ptr<ReportingDeliveryAgent> delivery_agent_;
 
+  // |persister_| must come after |delegate_|, |clock_|, |tick_clock_|, and
+  // |cache_|.
+  std::unique_ptr<ReportingPersister> persister_;
+
   // |garbage_collector_| must come after |tick_clock_| and |cache_|.
   std::unique_ptr<ReportingGarbageCollector> garbage_collector_;