AffiliationBackend: Implement the better part of on-demand fetching.

components/password_manager/core/browser/affiliation_utils.cc

Index: components/password_manager/core/browser/affiliation_utils.cc
diff --git a/components/password_manager/core/browser/affiliation_utils.cc b/components/password_manager/core/browser/affiliation_utils.cc
index ad9e0ac6ec49574affe252e8b545d8e474bdf344..23de0888f10eb74166816650c07644adf92f40bc 100644
--- a/components/password_manager/core/browser/affiliation_utils.cc
+++ b/components/password_manager/core/browser/affiliation_utils.cc
@@ -5,6 +5,7 @@
 #include "components/password_manager/core/browser/affiliation_utils.h"
 
 #include <algorithm>
+#include <ostream>
 
 #include "base/base64.h"
 #include "base/strings/string_piece.h"
@@ -268,6 +269,10 @@ AffiliatedFacetsWithUpdateTime::~AffiliatedFacetsWithUpdateTime() {
 
 // Helpers --------------------------------------------------------------------
 
+std::ostream& operator<<(std::ostream& os, const FacetURI& facet_uri) {
+  return os << facet_uri.potentially_invalid_spec();
+}
+
 bool AreEquivalenceClassesEqual(const AffiliatedFacets& a,
                                 const AffiliatedFacets& b) {
   if (a.size() != b.size())