Record the number of freshness periods since a stale HttpCache entry was last used

net/http/mock_http_cache.cc

Index: net/http/mock_http_cache.cc
diff --git a/net/http/mock_http_cache.cc b/net/http/mock_http_cache.cc
index 3f8cce4bc0a2cde211978c9055017ec976ed5067..682aff529ada0053bdc0e46d7fea8e7c0f18d40e 100644
--- a/net/http/mock_http_cache.cc
+++ b/net/http/mock_http_cache.cc
@@ -83,11 +83,11 @@ std::string MockDiskEntry::GetKey() const {
 }
 
 base::Time MockDiskEntry::GetLastUsed() const {
-  return base::Time::FromInternalValue(0);
+  return base::Time::Now();
 }
 
 base::Time MockDiskEntry::GetLastModified() const {
-  return base::Time::FromInternalValue(0);
+  return base::Time::Now();
 }
 
 int32_t MockDiskEntry::GetDataSize(int index) const {