Adds cache lock timeout handling after finishing headers phase.

net/http/http_cache.h

 // 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.
 
 // This file declares a HttpTransactionFactory implementation that can be
 // layered on top of another HttpTransactionFactory to add HTTP caching.  The
 // caching logic follows RFC 7234 (any exceptions are called out in the code).
 //
 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
 // the cache storage.
@@ skipping 177 matching lines @@
   void CloseIdleConnections();
 
   // Called whenever an external cache in the system reuses the resource
   // referred to by |url| and |http_method|.
   void OnExternalCacheHit(const GURL& url, const std::string& http_method);
 
   // Causes all transactions created after this point to simulate lock timeout
   // and effectively bypass the cache lock whenever there is lock contention.
   void SimulateCacheLockTimeout() { bypass_lock_for_test_ = true; }
 
+  // Causes all transactions created after this point to simulate lock timeout
+  // and effectively bypass the cache lock whenever there is lock contention
+  // after the transaction has completed its headers phase.
+  void SimulateCacheLockTimeoutAfterHeaders() {

[Randy Smith (Not in Mondays), 2017/06/23 17:38:01]

nit: Can this method have a ForTesting suffix?  I think there are some automated
tools that make sure such methods are only called from test code.

[shivanisha, 2017/06/23 19:16:08]

Done for both this and the existing SimulateCacheLockTimeout method

+    bypass_lock_after_headers_for_test_ = true;
+  }
+
   // Causes all transactions created after this point to generate a failure
   // when attempting to conditionalize a network request.
   void FailConditionalizationForTest() {
     fail_conditionalization_for_test_ = true;
   }
 
   // HttpTransactionFactory implementation:
   int CreateTransaction(RequestPriority priority,
                         std::unique_ptr<HttpTransaction>* trans) override;
   HttpCache* GetCache() override;
@@ skipping 298 matching lines @@
   void OnBackendCreated(int result, PendingOp* pending_op);
 
   // Variables ----------------------------------------------------------------
 
   NetLog* net_log_;
 
   // Used when lazily constructing the disk_cache_.
   std::unique_ptr<BackendFactory> backend_factory_;
   bool building_backend_;
   bool bypass_lock_for_test_;
+  bool bypass_lock_after_headers_for_test_;
   bool fail_conditionalization_for_test_;
 
   Mode mode_;
 
   std::unique_ptr<HttpTransactionFactory> network_layer_;
 
   std::unique_ptr<disk_cache::Backend> disk_cache_;
 
   // The set of active entries indexed by cache key.
   ActiveEntriesMap active_entries_;
@@ skipping 12 matching lines @@
   THREAD_CHECKER(thread_checker_);
 
   base::WeakPtrFactory<HttpCache> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpCache);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_H_