Serve offline page for online URL on disconnected or bad networks

chrome/browser/android/offline_pages/offline_page_request_interceptor.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_INTERCEPTOR_H_
+#define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_INTERCEPTOR_H_
+
+#include "base/macros.h"
+#include "net/url_request/url_request_interceptor.h"
+
+namespace net {
+class NetworkDelegate;
+class URLRequest;
+class URLRequestJob;
+}
+
+namespace offline_pages {
+
+// An interceptor to hijack requests and potentially service them based on
+// their offline information. Created one per profile.
+class OfflinePageRequestInterceptor : public net::URLRequestInterceptor {
+ public:
+  // |profile_id|, which identifies the profile, is passed as a void* to ensure
+  // it's not accidently used on the IO thread.
+  explicit OfflinePageRequestInterceptor(void* profile_id);
+  ~OfflinePageRequestInterceptor() override;
+
+ private:
+  // Overrides from net::URLRequestInterceptor:
+  net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const override;
+
+  // The profile for processing offline pages.
+  void* const profile_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(OfflinePageRequestInterceptor);
+};
+
+}  // namespace offline_pages
+
+#endif // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_INTERCEPTOR_H_