[Cronet] Purge storage directory if version does not match

components/cronet/url_request_context_config.cc

 // Copyright 2014 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 "components/cronet/url_request_context_config.h"
 
 #include <utility>
 
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/values.h"
 #include "net/cert/cert_verifier.h"
 #include "net/dns/host_resolver.h"
 #include "net/http/http_server_properties.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_utils.h"
 #include "net/socket/ssl_client_socket.h"
 #include "net/url_request/url_request_context_builder.h"
 
 namespace cronet {
 
 namespace {
 
+// Name of disk cache directory.
+const char kDiskCacheDirectoryName[] = "disk_cache";
 // TODO(xunjieli): Refactor constants in io_thread.cc.
 const char kQuicFieldTrialName[] = "QUIC";
 const char kQuicConnectionOptions[] = "connection_options";
 const char kQuicStoreServerConfigsInProperties[] =
     "store_server_configs_in_properties";
 const char kQuicMaxServerConfigsStoredInProperties[] =
     "max_server_configs_stored_in_properties";
 const char kQuicDelayTcpRace[] = "delay_tcp_race";
 const char kQuicMaxNumberOfLossyConnections[] =
     "max_number_of_lossy_connections";
@@ skipping 231 matching lines @@
 
 void URLRequestContextConfig::ConfigureURLRequestContextBuilder(
     net::URLRequestContextBuilder* context_builder,
     net::NetLog* net_log,
     const scoped_refptr<base::SequencedTaskRunner>& file_task_runner) {
   std::string config_cache;
   if (http_cache != DISABLED) {
     net::URLRequestContextBuilder::HttpCacheParams cache_params;
     if (http_cache == DISK && !storage_path.empty()) {
       cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::DISK;
-      cache_params.path = base::FilePath(storage_path);
+      cache_params.path =
+          base::FilePath(storage_path)
+              .Append(FILE_PATH_LITERAL(kDiskCacheDirectoryName));

[mef, 2016/04/05 18:00:50]

Do we have and/or need a test that 'disk_cache' directory gets created?

[xunjieli, 2016/04/05 18:22:55]

Done. Added the assertions in the original tests.

     } else {
       cache_params.type =
           net::URLRequestContextBuilder::HttpCacheParams::IN_MEMORY;
     }
     cache_params.max_size = http_cache_max_size;
     context_builder->EnableHttpCache(cache_params);
   } else {
     context_builder->DisableHttpCache();
   }
   context_builder->set_user_agent(user_agent);
   context_builder->SetSpdyAndQuicEnabled(enable_spdy, enable_quic);
   context_builder->set_sdch_enabled(enable_sdch);
   if (enable_quic)
     context_builder->set_quic_user_agent_id(quic_user_agent_id);
 
   ParseAndSetExperimentalOptions(experimental_options, context_builder, net_log,
                                  file_task_runner);
 
   if (mock_cert_verifier)
     context_builder->SetCertVerifier(std::move(mock_cert_verifier));
   // TODO(mef): Use |config| to set cookies.
 }
 
 }  // namespace cronet