Mojo's network service should use a disk cache on Android

mojo/services/network/network_context.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 "mojo/services/network/network_context.h"
 
 #include "base/base_paths.h"
 #include "base/path_service.h"
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
@@ skipping 18 matching lines @@
 scoped_ptr<net::URLRequestContext> NetworkContext::MakeURLRequestContext(
     const base::FilePath& base_path) {
   net::URLRequestContextBuilder builder;
   builder.set_accept_language("en-us,en");
   // TODO(darin): This is surely the wrong UA string.
   builder.set_user_agent("Mojo/0.1");
   builder.set_proxy_service(net::ProxyService::CreateDirect());
   builder.set_transport_security_persister_path(base_path);
 
   net::URLRequestContextBuilder::HttpCacheParams cache_params;
+#if defined(OS_ANDROID)
+  // On Android, we store the cache on disk becase we can run only a single
+  // instance of the shell at a time.
+  cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::DISK;
   cache_params.path = base_path.Append(FILE_PATH_LITERAL("Cache"));
-  // TODO(esprehn): For now store the cache in memory so we can run many shells
+#else
+  // On desktop, we store the cache in memory so we can run many shells
   // in parallel when running tests, otherwise the network services in each
   // shell will corrupt the disk cache.
   cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::IN_MEMORY;
+#endif
+
   builder.EnableHttpCache(cache_params);
-
   builder.set_file_enabled(true);
-
   return make_scoped_ptr(builder.Build());
 }
 
 }  // namespace mojo