Update from https://crrev.com/312398

net/test/url_request/url_request_slow_download_job.h

+// Copyright (c) 2012 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.
+// This class simulates a slow download. Requests to |kUnknownSizeUrl| and
+// |kKnownSizeUrl| start downloads that pause after the first N bytes, to be
+// completed by sending a request to |kFinishDownloadUrl|.
+
+#ifndef NET_TEST_URL_REQUEST_URL_REQUEST_SLOW_DOWNLOAD_JOB_H_
+#define NET_TEST_URL_REQUEST_URL_REQUEST_SLOW_DOWNLOAD_JOB_H_
+
+#include <set>
+#include <string>
+
+#include "base/lazy_instance.h"
+#include "base/memory/weak_ptr.h"
+#include "net/url_request/url_request_job.h"
+
+namespace net {
+
+class URLRequestSlowDownloadJob : public URLRequestJob {
+ public:
+  // Test URLs.
+  static const char kUnknownSizeUrl[];
+  static const char kKnownSizeUrl[];
+  static const char kFinishDownloadUrl[];
+  static const char kErrorDownloadUrl[];
+
+  // Download sizes.
+  static const int kFirstDownloadSize;
+  static const int kSecondDownloadSize;
+
+  // Timer callback, used to check to see if we should finish our download and
+  // send the second chunk.
+  void CheckDoneStatus();
+
+  // URLRequestJob methods
+  void Start() override;
+  bool GetMimeType(std::string* mime_type) const override;
+  void GetResponseInfo(HttpResponseInfo* info) override;
+  bool ReadRawData(IOBuffer* buf, int buf_size, int* bytes_read) override;
+
+  static URLRequestJob* Factory(URLRequest* request,
+                                NetworkDelegate* network_delegate,
+                                const std::string& scheme);
+
+  // Returns the current number of URLRequestSlowDownloadJobs that have
+  // not yet completed.
+  static size_t NumberOutstandingRequests();
+
+  // Adds the testing URLs to the URLRequestFilter.
+  static void AddUrlHandler();
+
+ private:
+  URLRequestSlowDownloadJob(URLRequest* request,
+                            NetworkDelegate* network_delegate);
+  ~URLRequestSlowDownloadJob() override;
+
+  // Enum indicating where we are in the read after a call to
+  // FillBufferHelper.
+  enum ReadStatus {
+    // The buffer was filled with data and may be returned.
+    BUFFER_FILLED,
+
+    // No data was added to the buffer because kFinishDownloadUrl has
+    // not yet been seen and we've already returned the first chunk.
+    REQUEST_BLOCKED,
+
+    // No data was added to the buffer because we've already returned
+    // all the data.
+    REQUEST_COMPLETE
+  };
+  ReadStatus FillBufferHelper(IOBuffer* buf, int buf_size, int* bytes_written);
+
+  void GetResponseInfoConst(HttpResponseInfo* info) const;
+
+  // Mark all pending requests to be finished.  We keep track of pending
+  // requests in |pending_requests_|.
+  static void FinishPendingRequests();
+  static void ErrorPendingRequests();
+  typedef std::set<URLRequestSlowDownloadJob*> SlowJobsSet;
+  static base::LazyInstance<SlowJobsSet>::Leaky pending_requests_;
+
+  void StartAsync();
+
+  void set_should_finish_download() { should_finish_download_ = true; }
+  void set_should_error_download() { should_error_download_ = true; }
+
+  int bytes_already_sent_;
+  bool should_error_download_;
+  bool should_finish_download_;
+  scoped_refptr<IOBuffer> buffer_;
+  int buffer_size_;
+
+  base::WeakPtrFactory<URLRequestSlowDownloadJob> weak_factory_;
+};
+
+}  // namespace content
+
+#endif  // NET_TEST_URL_REQUEST_URL_REQUEST_SLOW_DOWNLOAD_JOB_H_