Update DataReductionProxyNetworkDelegate/BypassStats to post tasks safely.

components/data_reduction_proxy/core/browser/BUILD.gn

 # 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.
 
 static_library("browser") {
   sources = [
     "data_reduction_proxy_bypass_protocol.cc",
     "data_reduction_proxy_bypass_protocol.h",
     "data_reduction_proxy_bypass_stats.cc",
     "data_reduction_proxy_bypass_stats.h",
@@ skipping 73 matching lines @@
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "data_reduction_proxy_bypass_protocol_unittest.cc",
     "data_reduction_proxy_bypass_stats_unittest.cc",
+    "data_reduction_proxy_compression_stats_unittest.cc",
     "data_reduction_proxy_config_service_client_unittest.cc",
     "data_reduction_proxy_config_unittest.cc",
     "data_reduction_proxy_configurator_unittest.cc",
     "data_reduction_proxy_interceptor_unittest.cc",
+    "data_reduction_proxy_io_data_unittest.cc",
     "data_reduction_proxy_metrics_unittest.cc",
     "data_reduction_proxy_network_delegate_unittest.cc",
     "data_reduction_proxy_prefs_unittest.cc",
     "data_reduction_proxy_request_options_unittest.cc",
     "data_reduction_proxy_settings_unittest.cc",
   ]
 
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   deps = [
     ":browser",
     ":test_support",
     "//base",
     "//base:prefs_test_support",
     "//base/test:test_support",
     "//components/data_reduction_proxy/core/common:test_support",
     "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }