[Android Downloads] Long-press menu item "Download Link" should delegate job to OfflinePages backen…

chrome/browser/android/offline_pages/downloads/resource_throttle.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_DOWNLOADS_RESOURCE_THROTTLE_H_
+#define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_DOWNLOADS_RESOURCE_THROTTLE_H_
+
+#include "content/public/browser/resource_throttle.h"
+#include "net/url_request/url_request.h"
+
+namespace offline_pages {
+namespace downloads {
+
+// This ResourceThrottle is used to hook up into the loading process at the
+// moment when headers are available (WillProcessResponse) to determine if the
+// download has text/html mime type and should be canceled as a download and
+// re-scheduled as a OfflinePage download request. This will be handled by
+// Offline Page backend as a full page download rather than a single .html
+// file download.
+class ResourceThrottle : public content::ResourceThrottle {
+ public:
+  explicit ResourceThrottle(const net::URLRequest* request);
+  ~ResourceThrottle() override;
+
+  // content::ResourceThrottle implementation:
+  void WillProcessResponse(bool* defer) override;
+  const char* GetNameForLogging() const override;
+
+ private:
+  const net::URLRequest* request_;
+
+  DISALLOW_COPY_AND_ASSIGN(ResourceThrottle);
+};
+
+}  // namespace downloads
+}  // namespace offline_pages
+
+#endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_DOWNLOADS_RESOURCE_THROTTLE_H_