Bounce all requests off the cache lock after 25ms.

net/http/http_cache_transaction.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 HttpCache::Transaction, a private class of HttpCache so
 // it should only be included by http_cache.cc
 
 #ifndef NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 #define NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 
@@ skipping 101 matching lines @@
   // Returns the LoadState of the writer transaction of a given ActiveEntry. In
   // other words, returns the LoadState of this transaction without asking the
   // http cache, because this transaction should be the one currently writing
   // to the cache entry.
   LoadState GetWriterLoadState() const;
 
   const CompletionCallback& io_callback() { return io_callback_; }
 
   const BoundNetLog& net_log() const;
 
-  // Bypasses the cache lock whenever there is lock contention.
-  void BypassLockForTest() {
-    bypass_lock_for_test_ = true;
-  }
-
   // Generates a failure when attempting to conditionalize a network request.
   void FailConditionalizationForTest() {
     fail_conditionalization_for_test_ = true;
   }
 
   // HttpTransaction methods:
   int Start(const HttpRequestInfo* request_info,
             const CompletionCallback& callback,
             const BoundNetLog& net_log) override;
   int RestartIgnoringLastError(const CompletionCallback& callback) override;
@@ skipping 314 matching lines @@
   bool reading_;  // We are already reading. Never reverts to false once set.
   bool invalid_range_;  // We may bypass the cache for this request.
   bool truncated_;  // We don't have all the response data.
   bool is_sparse_;  // The data is stored in sparse byte ranges.
   bool range_requested_;  // The user requested a byte range.
   bool handling_206_;  // We must deal with this 206 response.
   bool cache_pending_;  // We are waiting for the HttpCache.
   bool done_reading_;  // All available data was read.
   bool vary_mismatch_;  // The request doesn't match the stored vary data.
   bool couldnt_conditionalize_request_;
-  bool bypass_lock_for_test_;  // A test is exercising the cache lock.
   bool fail_conditionalization_for_test_;  // Fail ConditionalizeRequest.
   scoped_refptr<IOBuffer> read_buf_;
   int io_buf_len_;
   int read_offset_;
   int effective_load_flags_;
   int write_len_;
   scoped_ptr<PartialData> partial_;  // We are dealing with range requests.
   UploadProgress final_upload_progress_;
   CompletionCallback io_callback_;
 
@@ skipping 25 matching lines @@
   BeforeProxyHeadersSentCallback before_proxy_headers_sent_callback_;
 
   base::WeakPtrFactory<Transaction> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_