Implement ManifestFetcher, helper to fetch Web Manifests.

content/public/renderer/resource_fetcher.h

 // Copyright 2013 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_PUBLIC_RENDERER_RESOURCE_FETCHER_H_
 #define CONTENT_PUBLIC_RENDERER_RESOURCE_FETCHER_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
 
 class GURL;
 
 namespace base {
 class TimeDelta;
 }
 
 namespace blink {
 class WebFrame;
 class WebURLResponse;
 }
 
 namespace content {
 
 // Interface to download resources asynchronously.
 class CONTENT_EXPORT ResourceFetcher {
  public:
+  enum LoaderType {
+    PLATFORM_LOADER,         // uses Platform::createURLLoader
+    FRAME_ASSOCIATED_LOADER, // uses WebFrame::createAssociatedURLLoader
+  };
+
   virtual ~ResourceFetcher() {}
 
   // This will be called asynchronously after the URL has been fetched,
   // successfully or not.  If there is a failure, response and data will both be
   // empty.  |response| and |data| are both valid until the URLFetcher instance
   // is destroyed.
   typedef base::Callback<void(const blink::WebURLResponse& response,
                               const std::string& data)> Callback;
 
   // Creates a ResourceFetcher for the specified resource.  Caller takes
   // ownership of the returned object.  Deleting the ResourceFetcher will cancel
   // the request, and the callback will never be run.
   static ResourceFetcher* Create(const GURL& url);
 
   // Set the corresponding parameters of the request.  Must be called before
   // Start.  By default, requests are GETs with no body.
   virtual void SetMethod(const std::string& method) = 0;
   virtual void SetBody(const std::string& body) = 0;
   virtual void SetHeader(const std::string& header,
                          const std::string& value) = 0;
 
   // Starts the request using the specified frame.  Calls |callback| when
   // done.
   virtual void Start(blink::WebFrame* frame,
                      blink::WebURLRequest::RequestContext request_context,
                      blink::WebURLRequest::FrameType frame_type,
+                     LoaderType loader_type,
                      const Callback& callback) = 0;
 
   // Sets how long to wait for the server to reply.  By default, there is no
   // timeout.  Must be called after a request is started.
   virtual void SetTimeout(const base::TimeDelta& timeout) = 0;
+
+  // Manually cancel the request.
+  virtual void Cancel() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_RESOURCE_FETCHER_H_