Persist broken and recently-broken alt-svcs to prefs in HttpServerPropertiesManager

net/http/broken_alternative_services.h

Index: net/http/broken_alternative_services.h
diff --git a/net/http/broken_alternative_services.h b/net/http/broken_alternative_services.h
index cd1ab903c3f650c93a38ec5489f50923028c8361..46f6b8ba6369eb9f2b582ce08671cc8b37fa4161 100644
--- a/net/http/broken_alternative_services.h
+++ b/net/http/broken_alternative_services.h
@@ -9,13 +9,10 @@
 #include <unordered_map>
 
 #include "base/memory/weak_ptr.h"
+#include "base/time/default_tick_clock.h"
 #include "base/timer/timer.h"
 #include "net/http/http_server_properties.h"
 
-namespace base {
-class TickClock;
-}
-
 namespace net {
 
 // This class tracks HTTP alternative services that have been marked as broken.
@@ -84,6 +81,13 @@ class NET_EXPORT_PRIVATE BrokenAlternativeServices {
   // expiration time.
   // All AlternativeServices in |broken_alternative_service_list| must exist in
   // |recently_broken_alternative_services|.
+  //
+  // If a broken/recently-broken alt svc that's being added is already stored,
+  // the stored expiration/broken-count for that alt svc will be overwritten
+  // with the new value.
+  // However, |recently_broken_alternative_services_| will still have the
+  // already-stored alt svcs at the front of the recency list, followed by the
+  // newly added ones.
   void SetBrokenAndRecentlyBrokenAlternativeServices(
       std::unique_ptr<BrokenAlternativeServiceList>
           broken_alternative_service_list,