Some initial hookup of offline page request interception

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/supports_user_data.h"
+#include "content/public/common/resource_type.h"
+
+namespace net {
+class NetworkDelegate;
+class URLRequest;
+class URLRequestInterceptor;
+class URLRequestJob;
+}
+
+namespace offline_pages {
+
+// Class for servicing requests based on their offline information. Created one
+// per URLRequest and attached to each request.

[fgorski, 2016/08/10 16:26:10]

Please add a little longer comment that explains the relationship between the
interceptor and handler and what is the role each one of them plays in the
offline request handling.

[jianli, 2016/08/10 21:37:25]

Done.

+class OfflinePageRequestHandler : public base::SupportsUserData::Data {
+ public:
+  // Attaches a newly created handler if the given |request| needs to

[fgorski, 2016/08/10 16:26:10]

is there something missing in this sentence?
If yes, please add, if not please put a "." at the end.

[jianli, 2016/08/10 21:37:25]

Done.

+  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);

[fgorski, 2016/08/10 16:26:10]

please document profile_id and explain why it is void*
I have hard time understanding this code.

[jianli, 2016/08/10 21:37:25]

Done.

+
+  ~OfflinePageRequestHandler() override;
+
+  net::URLRequestJob* MaybeCreateJob(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate,
+      void* profile_id);
+
+ private:
+  OfflinePageRequestHandler();
+
+  DISALLOW_COPY_AND_ASSIGN(OfflinePageRequestHandler);
+};
+
+}  // namespace offline_pages
+
+#endif // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_HANDLER_H_