Add support for subresource request fallback in AppCache for the network service..

content/browser/appcache/appcache_request.h

 // Copyright (c) 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_REQUEST_H_
 #define CONTENT_BROWSER_APPCACHE_APPCACHE_REQUEST_H_
 
 #include "base/logging.h"
 #include "base/sequence_checker.h"
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "url/gurl.h"
 
 namespace net {
 class URLRequest;
 }
 
 namespace content {
+class AppCacheURLLoaderRequest;
+class AppCacheURLRequest;
 struct ResourceRequest;
 
 // Interface for an AppCache request. Subclasses implement this interface to
 // wrap custom request objects like URLRequest, etc to ensure that these
 // dependencies stay out of the AppCache code.
 class CONTENT_EXPORT AppCacheRequest {
  public:
   virtual ~AppCacheRequest();
 
   // The URL for this request.
@@ skipping 22 matching lines @@
 
   // Get response header(s) by name. Returns an empty string if the header
   // wasn't found,
   virtual std::string GetResponseHeaderByName(
       const std::string& name) const = 0;
 
   // Returns true if the scheme and method are supported for AppCache.
   static bool IsSchemeAndMethodSupportedForAppCache(
       const AppCacheRequest* request);
 
+  // Returns the underlying AppCacheURLRequest if any. This only applies to
+  // AppCache requests loaded via the URLRequest mechanism
+  virtual AppCacheURLRequest* AsURLRequest();
+
+  // Returns the underlying AppCacheURLLoaderRequest if any. This only applies
+  // to AppCache requests loaded via the URLLoader mechanism.
+  virtual AppCacheURLLoaderRequest* AsURLLoaderRequest();
+
  protected:
   friend class AppCacheRequestHandler;
   // Enables the AppCacheJob to call GetURLRequest() and GetResourceRequest().
   friend class AppCacheJob;
 
   AppCacheRequest() {}
 
   // Getters for the request types we currently support.
   virtual net::URLRequest* GetURLRequest();
 
   // Returns the underlying ResourceRequest. Please note that only one of
   // GetURLRequest() and GetResourceRequest() should return valid results.
   virtual ResourceRequest* GetResourceRequest();
 
   SEQUENCE_CHECKER(sequence_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(AppCacheRequest);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_APPCACHE_APPCACHE_REQUEST_H_