Get rid of URLLoaderFactory in browser-side case

content/browser/loader/url_loader_request_handler.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_LOADER_URL_LOADER_REQUEST_HANDLER_H_
 #define CONTENT_BROWSER_LOADER_URL_LOADER_REQUEST_HANDLER_H_
 
+#include <memory>
 #include "base/callback_forward.h"
 #include "base/macros.h"
-#include "content/common/url_loader_factory.mojom.h"
+#include "content/common/url_loader.mojom.h"
 
 namespace content {
 
 class ResourceContext;
 struct ResourceRequest;
 
-using LoaderFactoryCallback =
-    base::OnceCallback<void(mojom::URLLoaderFactory*)>;
+using StartLoaderCallback =
+    base::OnceCallback<void(mojom::URLLoaderAssociatedRequest request,
+                            mojom::URLLoaderClientPtr client)>;
+
+using LoaderCallback = base::OnceCallback<void(StartLoaderCallback)>;
 
 // An instance of this class is a per-request object and kept around during
 // the lifetime of a request (including multiple redirect legs) on IO thread.
 class CONTENT_EXPORT URLLoaderRequestHandler {
  public:
   URLLoaderRequestHandler() = default;
   virtual ~URLLoaderRequestHandler() = default;
 
-  // Calls |callback| with non-null factory if this handler can handle
-  // the request, calls it with nullptr otherwise.
-  // Some implementation notes:
-  // 1) The returned pointer needs to be valid only until a single
-  // CreateLoaderAndStart call is made, and it is okay to do CHECK(false) for
-  // any subsequent calls.
-  // 2) The implementor is not supposed to set up and return URLLoaderFactory
-  // until it finds out that the handler is really going to handle the
-  // request. (For example ServiceWorker's request handler would not need to
-  // call the callback until it gets response from SW, and it may still
-  // call the callback with nullptr if it turns out that it needs to fallback
-  // to the network.)
-  virtual void MaybeCreateLoaderFactory(const ResourceRequest& resource_request,
-                                        ResourceContext* resource_context,
-                                        LoaderFactoryCallback callback) = 0;
+  // Calls |callback| with a non-null StartLoaderCallback if this handler
+  // can handle the request, calls it with null callback otherwise.
+  virtual void MaybeCreateLoader(const ResourceRequest& resource_request,
+                                 ResourceContext* resource_context,
+                                 LoaderCallback callback) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_URL_LOADER_REQUEST_HANDLER_H_