Handle online and offline redirects via interceptor and offline scheme

chrome/browser/android/offline_pages/offline_page_request_handler.h

+// Copyright 2016 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 CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_HANDLER_H_
+#define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_HANDLER_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/supports_user_data.h"
+#include "chrome/browser/android/offline_pages/offline_page_request_redirect_job.h"
+#include "content/public/common/resource_type.h"
+
+namespace net {
+class NetworkDelegate;
+class URLRequest;
+class URLRequestInterceptor;
+}
+
+namespace offline_pages {
+
+// Class for servicing requests based on their offline information. Created one
+// per URLRequest and attached to each request.
+class OfflinePageRequestHandler :
+    public base::SupportsUserData::Data,
+    public OfflinePageRequestRedirectJob::Delegate {
+ public:
+  // Attaches a newly created handler if the given |request| needs to
+  // be handled by offline pages.
+  static void InitializeHandler(net::URLRequest* request,
+                                content::ResourceType resource_type);
+
+  // Returns the handler attached to |request|. This may return null
+  // if no handler is attached.
+  static OfflinePageRequestHandler* GetHandler(net::URLRequest* request);
+
+  // Creates a protocol interceptor for offline pages.
+  static std::unique_ptr<net::URLRequestInterceptor> CreateInterceptor(
+      void* profile_id);
+
+  ~OfflinePageRequestHandler() override;
+
+  // OfflinePageRequestRedirectJob::Delegate overrides:
+  void OnPrepareToRestart() override;
+
+  net::URLRequestJob* MaybeCreateJob(net::URLRequest* request,
+                                     net::NetworkDelegate* network_delegate,
+                                     void* profile_id);
+
+ private:
+  OfflinePageRequestHandler();
+
+  // Invoked from UI thread.
+  void GetRedirectUrl(const GURL& url, void* profile_id);
+
+  base::WeakPtr<OfflinePageRequestRedirectJob> redirect_job_;
+
+  // True if the next time this request is started, the request should be
+  // serviced from the default handler.
+  bool use_default_ = false;
+
+  base::WeakPtrFactory<OfflinePageRequestHandler> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(OfflinePageRequestHandler);
+};
+
+}  // namespace offline_pages
+
+#endif // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_HANDLER_H_