Get main frame and subframe AppCache loads to work.

content/browser/loader/navigation_url_loader_network_service.cc

 // Copyright 2017 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 "content/browser/loader/navigation_url_loader_network_service.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/appcache/appcache_navigation_handle.h"
+#include "content/browser/appcache/appcache_request_handler.h"
 #include "content/browser/blob_storage/chrome_blob_storage_context.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigation_request_info.h"
 #include "content/browser/loader/navigation_resource_handler.h"
 #include "content/browser/loader/navigation_resource_throttle.h"
 #include "content/browser/loader/navigation_url_loader_delegate.h"
 #include "content/browser/loader/url_loader_request_handler.h"
 #include "content/browser/resource_context_impl.h"
 #include "content/browser/service_worker/service_worker_navigation_handle.h"
 #include "content/browser/service_worker/service_worker_navigation_handle_core.h"
@@ skipping 137 matching lines @@
               service_worker_navigation_handle_core, blob_storage_context,
               request_info->begin_params.skip_service_worker, resource_type,
               request_info->begin_params.request_context_type, frame_type,
               request_info->are_ancestors_secure,
               request_info->common_params.post_data, web_contents_getter);
       if (service_worker_handler)
         handlers_.push_back(std::move(service_worker_handler));
     }
 
     if (appcache_handle_core) {
-      // TODO: add appcache code here.
+      std::unique_ptr<URLLoaderRequestHandler> appcache_handler =
+          AppCacheRequestHandler::InitializeForNavigationNetworkService(
+              *resource_request_, appcache_handle_core);
+      if (appcache_handler)
+        handlers_.push_back(std::move(appcache_handler));
     }
 
     Restart(std::move(url_loader_request), std::move(url_loader_client_ptr_));
   }
 
   // This could be called multiple times.
   void Restart(mojom::URLLoaderRequest url_loader_request,
                mojom::URLLoaderClientPtr url_loader_client_ptr) {
     url_loader_request_ = std::move(url_loader_request);
     url_loader_client_ptr_ = std::move(url_loader_client_ptr);
@@ skipping 209 matching lines @@
     TRACE_EVENT_ASYNC_END2("navigation", "Navigation timeToResponseStarted",
                            this, "&NavigationURLLoaderNetworkService", this,
                            "success", false);
 
     delegate_->OnRequestFailed(completion_status.exists_in_cache,
                                completion_status.error_code);
   }
 }
 
 }  // namespace content