[Cronet] Purge storage directory if version does not match

components/cronet/url_request_context_config.cc

Index: components/cronet/url_request_context_config.cc
diff --git a/components/cronet/url_request_context_config.cc b/components/cronet/url_request_context_config.cc
index 66f9fb06e053ac65bbd6bd6244bb171a4529129a..5d1a00bcc3a2ab00dfa1bda1631d9e2e25b023e9 100644
--- a/components/cronet/url_request_context_config.cc
+++ b/components/cronet/url_request_context_config.cc
@@ -25,6 +25,8 @@ 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";
@@ -276,7 +278,9 @@ void URLRequestContextConfig::ConfigureURLRequestContextBuilder(
     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;