RFC: use some in-memory state in SimpleCache to quickly cache-miss some CantConditionalize cases

net/disk_cache/disk_cache.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/metrics/field_trial.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 163 matching lines @@
     *backend = disk_cache::MemBackendImpl::CreateBackend(max_bytes, net_log);
     return *backend ? net::OK : net::ERR_FAILED;
   }
   DCHECK(thread.get());
   CacheCreator* creator =
       new CacheCreator(path, force, max_bytes, type, backend_type, kNone,
                        thread, net_log, backend, callback);
   return creator->Run();
 }
 
+int Backend::OpenEntryWithOracleByte(const std::string& key,
+                                     Entry** entry,
+                                     const OracleCallback& oracle,
+                                     const CompletionCallback& callback) {
+  return OpenEntry(key, entry, callback);
+}
+
 int Backend::CalculateSizeOfEntriesBetween(base::Time initial_time,
                                            base::Time end_time,
                                            const CompletionCallback& callback) {
   return net::ERR_NOT_IMPLEMENTED;
 }
 
+void Entry::SetOracleByte(uint8_t) {}
+
 }  // namespace disk_cache