Adds a new class HttpCache::Writers for multiple cache transactions reading from the network.

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 149 matching lines @@
   void SetBeforeNetworkStartCallback(
       const BeforeNetworkStartCallback& callback) override;
   void SetBeforeHeadersSentCallback(
       const BeforeHeadersSentCallback& callback) override;
   int ResumeNetworkStart() override;
   void GetConnectionAttempts(ConnectionAttempts* out) const override;
 
   // Returns the estimate of dynamically allocated memory in bytes.
   size_t EstimateMemoryUsage() const;
 
+  RequestPriority priority() { return priority_; }

[jkarlin, 2017/06/12 18:30:32]

this should be a const function

[shivanisha, 2017/06/14 02:33:16]

done

+  PartialData* partial() { return partial_.get(); }
+
  private:
   static const size_t kNumValidationHeaders = 2;
   // Helper struct to pair a header name with its value, for
   // headers used to validate cache entries.
   struct ValidationHeaders {
     ValidationHeaders() : initialized(false) {}
 
     std::string values[kNumValidationHeaders];
     bool initialized;
   };
@@ skipping 335 matching lines @@
   bool in_do_loop_;
 
   base::WeakPtrFactory<Transaction> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_