Get main frame and subframe AppCache loads to work.

content/browser/appcache/appcache_url_loader_factory.h

 // 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.
 
 #ifndef CONTENT_BROWSER_APPCACHE_APPCACHE_URL_LOADER_FACTORY_H_
 #define CONTENT_BROWSER_APPCACHE_APPCACHE_URL_LOADER_FACTORY_H_
 
 #include "base/memory/ref_counted.h"
 #include "content/common/url_loader_factory.mojom.h"
 #include "mojo/public/cpp/bindings/strong_binding_set.h"
 #include "url/gurl.h"
 
 namespace content {
+class AppCacheNavigationHandleCore;
+class AppCacheURLLoader;
 class ChromeAppCacheService;
 class URLLoaderFactoryGetter;
+class URLLoaderRequestHandler;
 
 // Implements the URLLoaderFactory mojom for AppCache requests.
 class AppCacheURLLoaderFactory : public mojom::URLLoaderFactory {
  public:
   ~AppCacheURLLoaderFactory() override;
 
   // Factory function to create an instance of the factory.
-  // The |appcache_service| parameter is used to query the underlying
-  // AppCacheStorage instance to check if we can service requests from the
-  // AppCache. We pass unhandled requests to the network service retrieved from
-  // the |factory_getter|.
+  // 1. The |appcache_service| parameter is passed to the URLLoader mojom for
+  //    checking if the request can be serviced from the AppCache.
+  // 2. The |factory_getter| parameter is used to query the network service
+  //    to pass network requests to.
+  // 3. The |navigation_url_loader| is valid only for navigation requests. In
+  //    other cases like subresource requests we create an instance of the
+  //    AppCacheURLLoader class to handle the request.
+  // 4. The process_id parameter identifies the process. 0 for browser
+  //    initiated  requests.
   static void CreateURLLoaderFactory(mojom::URLLoaderFactoryRequest request,

[jam, 2017/06/01 15:00:46]

this isn't called externally anymore, so no need to keep it in the header?

[ananta, 2017/06/01 17:28:01]

The static function uses the loader_factory_bindings_ member.

                                      ChromeAppCacheService* appcache_service,
-                                     URLLoaderFactoryGetter* factory_getter);
+                                     URLLoaderFactoryGetter* factory_getter,
+                                     AppCacheURLLoader* navigation_url_loader,
+                                     int process_id);
+
+  // Creates an instance of the URLLoaderRequestHandler subclass to see if we
+  // can serve this request from the AppCache.
+  static std::unique_ptr<URLLoaderRequestHandler> CreateRequestHandler(
+      AppCacheNavigationHandleCore* appcache_handle_core,
+      URLLoaderFactoryGetter* url_loader_factory_getter);
 
   // mojom::URLLoaderFactory implementation.
   void CreateLoaderAndStart(mojom::URLLoaderRequest url_loader_request,
                             int32_t routing_id,
                             int32_t request_id,
                             uint32_t options,
                             const ResourceRequest& request,
                             mojom::URLLoaderClientPtr client) override;
   void SyncLoad(int32_t routing_id,
                 int32_t request_id,
                 const ResourceRequest& request,
                 SyncLoadCallback callback) override;
 
  private:
   AppCacheURLLoaderFactory(ChromeAppCacheService* appcache_service,
-                           URLLoaderFactoryGetter* factory_getter);
+                           URLLoaderFactoryGetter* factory_getter,
+                           AppCacheURLLoader* url_loader_instance,
+                           int process_id);
 
   // Used to query AppCacheStorage to see if a request can be served out of the
   /// AppCache.
   scoped_refptr<ChromeAppCacheService> appcache_service_;
 
   // Used to retrieve the network service factory to pass unhandled requests to
   // the network service.
   scoped_refptr<URLLoaderFactoryGetter> factory_getter_;
 
+  // Only set for navigation requests.
+  AppCacheURLLoader* navigation_url_loader_;
+
+  // Process id. 0 for browser.
+  int process_id_;
+
   mojo::StrongBindingSet<mojom::URLLoaderFactory> loader_factory_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(AppCacheURLLoaderFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_APPCACHE_APPCACHE_URL_LOADER_FACTORY_H_