[Clean-up] Remove NetworkStats code, which has been dead code since July 2014.

chrome/browser/net/network_stats.h

Index: chrome/browser/net/network_stats.h
diff --git a/chrome/browser/net/network_stats.h b/chrome/browser/net/network_stats.h
deleted file mode 100644
index 4ce6c4ebd3e0b94e967606f0400367f7f836065a..0000000000000000000000000000000000000000
--- a/chrome/browser/net/network_stats.h
+++ /dev/null
@@ -1,390 +0,0 @@
-// Copyright 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.
-
-#ifndef CHROME_BROWSER_NET_NETWORK_STATS_H_
-#define CHROME_BROWSER_NET_NETWORK_STATS_H_
-
-#include <bitset>
-#include <string>
-#include <vector>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram.h"
-#include "base/time/time.h"
-#include "chrome/browser/io_thread.h"
-#include "chrome/browser/net/probe_message.h"
-#include "net/base/address_list.h"
-#include "net/base/completion_callback.h"
-#include "net/base/host_port_pair.h"
-#include "net/base/io_buffer.h"
-#include "net/proxy/proxy_info.h"
-
-namespace net {
-class ClientSocketFactory;
-class DatagramClientSocket;
-class HostResolver;
-class SingleRequestHostResolver;
-}
-
-namespace chrome_browser_net {
-
-// This class is used for live experiment of network connectivity (for UDP)
-// metrics. A small percentage of users participate in this experiment. All
-// users (who are in the experiment) must have enabled "UMA upload".
-// In the experiments, clients request the server to send some probing packets,
-// collect some stats, and send back the results via UMA reports.
-//
-// This class collects the following stats from users who have opted in.
-// a) RTT.
-// b) packet inter-arrival time.
-// c) packet losses for correlation and FEC experiments.
-// d) packet losses for NAT binding test after idling for a certain period.
-//
-// There are three tests in one experiment. Right before each test, a
-// HelloRequest is sent to get an updated token.
-// 1. |START_PACKET_TEST|: 21 packets are sent from the server to the client
-//    without pacing.
-// 2. |PACED_PACKET_TEST| or |NON_PACED_PACKET_TEST|: After the first test,
-//    21 packets are sent from the server to the client with or without pacing.
-//    If pacing, the pacing rate is computed from the first test.
-// 3. |NAT_BIND_TEST|: 2 packets are sent from the server to the client with
-//    a randomly generated delay of 1~300 seconds.
-// At the end of these tests, we send another HelloRequest to test whether
-// the network is still connected and has not changed (e.g. from Wifi to 3g).
-
-class NetworkStats {
- public:
-  enum Status {            // Used in UMA_HISTOGRAM_ENUMERATION.
-    SUCCESS,               // Successfully received bytes from the server.
-    SOCKET_CREATE_FAILED,  // Socket creation failed.
-    RESOLVE_FAILED,        // Host resolution failed.
-    CONNECT_FAILED,        // Connection to the server failed.
-    WRITE_FAILED,          // Sending a message to the server failed.
-    READ_TIMED_OUT,        // Reading the reply from the server timed out.
-    READ_FAILED,           // Reading the reply from the server failed.
-    STATUS_MAX,            // Bounding value.
-  };
-
-  enum ReadState {         // Used to track if |socket_| has a pending read.
-    READ_STATE_IDLE,
-    READ_STATE_READ_PENDING,
-  };
-
-  enum WriteState {        // Used to track if |socket_| has a pending write.
-    WRITE_STATE_IDLE,
-    WRITE_STATE_WRITE_PENDING,
-  };
-
-  // |TestType| specifies the possible tests we may run
-  // (except for the first and the last serving as boundaries).
-  enum TestType {
-    // The first one is for requesting token, not a probe test. Put it here
-    // because we use it as a symbol for sending the HelloRequest packet to
-    // acquire the token.
-    TOKEN_REQUEST,
-    START_PACKET_TEST,      // First packet loss test (no pacing).
-    NON_PACED_PACKET_TEST,  // Packet loss test with no pacing.
-    PACED_PACKET_TEST,      // Packet loss test with pacing.
-    // Test whether NAT binding expires after some idle period.
-    NAT_BIND_TEST,
-    PACKET_SIZE_TEST,
-    TEST_TYPE_MAX,
-  };
-
-  // Pointer |socket_factory| is NOT deleted by this class.
-  explicit NetworkStats(net::ClientSocketFactory* socket_factory);
-  // NetworkStats is deleted in TestPhaseComplete() when all tests are done.
-  ~NetworkStats();
-
-  // Start the client and connect to |server|.
-  // A client will request a token and then perform several tests.
-  // When the client finishes all tests, or when an error occurs causing the
-  // client to stop, |TestPhaseComplete| will be called with a net status code.
-  // |TestPhaseComplete| will collect histogram stats.
-  // Return true if successful in starting the client.
-  bool Start(net::HostResolver* host_resolver,
-             const net::HostPortPair& server,
-             uint16 histogram_port,
-             bool has_proxy_server,
-             uint32 probe_bytes,
-             uint32 bytes_for_packet_size_test,
-             const net::CompletionCallback& callback);
-
- private:
-  friend class NetworkStatsTest;
-
-  // Start the test specified by the current_test_index_. It also resets all
-  // the book keeping data, before starting the new test.
-  void StartOneTest();
-
-  // Reset all the counters and the collected stats.
-  void ResetData();
-
-  // Callback that is called when host resolution is completed.
-  void OnResolveComplete(int result);
-
-  // Called after host is resolved. Creates UDPClientSocket and connects to the
-  // server. If successfully connected, then calls ConnectComplete() to start
-  // the network connectivity tests. Returns |false| if there is any error.
-  bool DoConnect(int result);
-
-  // This method is called after socket connection is completed. It will start
-  // the process of sending packets to |server| by calling SendHelloPacket().
-  // Return false if connection is not established (result is less than 0).
-  bool ConnectComplete(int result);
-
-  // Send a HelloRequest packet which asks for a token from the server. If
-  // a token is received, it will will add |START_PACKET_TEST| to the test
-  // queue.
-  void SendHelloRequest();
-
-  // Send a ProbeRequest packet which requests the server to send a set
-  // of Probing packets.
-  void SendProbeRequest();
-
-  // Read and process the data. Called from OnReadComplete() or ReadData().
-  // This function calls TestPhaseComplete() if there is a significant network
-  // error or if all packets in the current test are received.
-  // Return true if TestPhaseComplete() is called otherwise return false.
-  bool ReadComplete(int result);
-
-  // Callbacks when an internal IO (Read or Write) is completed.
-  void OnReadComplete(int result);
-  void OnWriteComplete(int result);
-
-  // Read data from server until an error or IO blocking occurs or reading is
-  // complete. Return the result value from socket reading and 0 if |socket_|
-  // is Null.
-  int ReadData();
-
-  // Send data contained in |str| to server.
-  // Return a negative value if IO blocking occurs or there is an error.
-  // Otherwise return net::OK.
-  int SendData(const std::string& str);
-
-  // Update the send buffer (telling it that |bytes_sent| has been sent).
-  // And reset |write_buffer_|.
-  void UpdateSendBuffer(int bytes_sent);
-
-  // Start a timer (with value |milliseconds|) for responses from the probe
-  // servers.  |test_index| is the index of the test at vector |test_sequence_|
-  // and it is used as a parameter of the timer callback.
-  void StartReadDataTimer(uint32 milliseconds, uint32 test_index);
-
-  // Called when the StartReadDataTimer fires. |test_index| specifies
-  // the index of the test. If |current_test_index_| has changed to a
-  // different value, it indicates |test_index| has completed, then
-  // this method is a no-op.
-  void OnReadDataTimeout(uint32 test_index);
-
-  // Collect network connectivity stats. This is called when all the data from
-  // server is read or when there is a failure during connect/read/write. It
-  // will either start the next phase of the test, or it will self destruct
-  // at the end of this method. Returns true if a new test wasn't started and it
-  // was self destructed.
-  bool TestPhaseComplete(Status status, int result);
-
-  // This method is called from TestPhaseComplete() and calls
-  // |finished_callback_| callback to indicate that the test has finished.
-  void DoFinishCallback(int result);
-
-  // Update counters/metrics for the given |probe_packet|.
-  // Return true if all packets for the current test are received and
-  // false otherwise.
-  bool UpdateReception(const ProbePacket& probe_packet);
-
-  // Record all histograms for current test phase, which is assumed to be
-  // complete (i.e., we are no longer waiting for packets in this phase).
-  // |test_type| is the current test_type to be recorded. |status| is the
-  // status of the current test.
-  void RecordHistograms(TestType test_type);
-
-  // Collect the following network connectivity stats when
-  // kMaximumSequentialPackets (21) packets are sent from the server.
-  // a) Client received at least one packet.
-  // b) Client received the nth packet.
-  // c) The number of packets received for each subsequence of packets 1...n.
-  void RecordPacketsReceivedHistograms(TestType test_type);
-
-  // Collect the following network connectivity stats for the first
-  // kMaximumCorrelationPackets (6) packets in a test.
-  // Success/failure of each packet, to estimate reachability for users,
-  // and to estimate if there is a probabalistic dependency in packet loss when
-  // kMaximumCorrelationPackets packets are sent consecutively.
-  void RecordPacketLossSeriesHistograms(TestType test_type);
-
-  // Collect the average inter-arrival time (scaled up by 20 times because the
-  // minimum time value in a histogram is 1ms) of a sequence of probing packets.
-  void RecordInterArrivalHistograms(TestType test_type);
-
-  // Collect the RTT for the packet specified by the |index| in the current
-  // test.
-  void RecordRTTHistograms(TestType test_type, uint32 index);
-
-  // Collect whether the second packet in the NAT test is received for the
-  // given idle time.
-  void RecordNATTestReceivedHistograms(Status status);
-
-  // Collect whether we have the requested packet size was received or not in
-  // the PACKET_SIZE_TEST test.
-  void RecordPacketSizeTestReceivedHistograms(Status status);
-
-  // Record the time duration between sending the probe request and receiving
-  // the last probe packet excluding the pacing time requested by the client.
-  // This applies to both NAT bind test and paced/non-paced packet test.
-  void RecordSendToLastRecvDelayHistograms(TestType test_type);
-
-  // Return the next test type (internally increment |current_test_index_|)
-  // in |test_sequence_|;
-  TestType GetNextTest();
-
-  // These static variables are defined so that they can be changed in testing.
-  // Maximum number of tests in one activation of the experiment.
-  static uint32 maximum_tests_;
-  // Maximum number of packets for START/PACED/NON_PACED tests.
-  static uint32 maximum_sequential_packets_;
-  // Maximum number of packets for NAT binding test.
-  static uint32 maximum_NAT_packets_;
-  // Maximum time duration between the two packets for NAT Bind testing.
-  static uint32 maximum_NAT_idle_seconds_;
-  // Whether to start the probe test immediately after connect success.
-  // Used for unittest.
-  static bool start_test_after_connect_;
-
-  // The socket handler for this session.
-  scoped_ptr<net::DatagramClientSocket> socket_;
-
-  net::ClientSocketFactory* socket_factory_;
-
-  // The read buffer used to read data from the socket.
-  scoped_refptr<net::IOBuffer> read_buffer_;
-
-  // The write buffer used to write data to the socket.
-  scoped_refptr<net::DrainableIOBuffer> write_buffer_;
-
-  // Specify the port for which we are testing the network connectivity.
-  uint16 histogram_port_;
-
-  // Specify if there is a proxy server or not.
-  bool has_proxy_server_;
-
-  // HostResolver used to find the IP addresses.
-  scoped_ptr<net::SingleRequestHostResolver> resolver_;
-
-  // Addresses filled out by HostResolver after host resolution is completed.
-  net::AddressList addresses_;
-
-  // Callback to call when test is successefully finished or whenever
-  // there is an error (this will be used by unittests to check the result).
-  net::CompletionCallback finished_callback_;
-
-  // RTTs for each packet.
-  std::vector<base::TimeDelta> packet_rtt_;
-
-  // Time when sending probe_request, used for computing RTT.
-  base::TimeTicks probe_request_time_;
-
-  // Size of the probe packets requested to be sent from servers. We don't use
-  // |probe_packet_bytes_| during PACKET_SIZE_TEST.
-  uint32 probe_packet_bytes_;
-
-  // Size of the packet requested to be sent from servers for PACKET_SIZE_TEST.
-  uint32 bytes_for_packet_size_test_;
-
-  // bitmask indicating which packets are received.
-  std::bitset<21> packets_received_mask_;
-
-  // Arrival time of the first packet in the current test.
-  base::TimeTicks first_arrival_time_;
-  // Arrival time of the most recently received packet in the current test.
-  base::TimeTicks last_arrival_time_;
-  // Average time between two consecutive packets. It is updated when either all
-  // packets are received or timeout happens in the current test.
-  base::TimeDelta inter_arrival_time_;
-  // Target time duration for sending two consecutive packets at the server.
-  // It should be 0 for StartPacket test or NonPacedPacket test. For
-  // PacedPacket test, it is derived from the inter_arrival_time_ in the
-  // previous (StartPacket) test. For NATBind test, it is randomly generated
-  // between 1 second and |maximum_NAT_idle_seconds_| seconds.
-  base::TimeDelta pacing_interval_;
-  // A list of tests that will be performed in sequence.
-  std::vector<TestType> test_sequence_;
-  uint32 current_test_index_;  // Index of the current test.
-
-  ProbeMessage probe_message_;
-
-  // Token received from server for authentication.
-  ProbePacket_Token token_;
-
-  // The state variables to track pending reads/writes.
-  ReadState read_state_;
-  WriteState write_state_;
-
-  // We use this factory to create timeout tasks for socket's ReadData.
-  base::WeakPtrFactory<NetworkStats> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(NetworkStats);
-};
-
-class ProxyDetector {
- public:
-  // Used for the callback that is called from |OnResolveProxyComplete|.
-  typedef base::Callback<void(bool)> OnResolvedCallback;
-
-  // Construct a ProxyDetector object that finds out if access to
-  // |server_address| goes through a proxy server or not. Calls the |callback|
-  // after proxy resolution is completed by currying the proxy resolution
-  // status.
-  ProxyDetector(net::ProxyService* proxy_service,
-                const net::HostPortPair& server_address,
-                OnResolvedCallback callback);
-
-  // This method uses |proxy_service_| to resolve the proxy for
-  // |server_address_|.
-  void StartResolveProxy();
-
- private:
-  // This object is deleted from |OnResolveProxyComplete|.
-  ~ProxyDetector();
-
-  // Call the |callback_| by currying the proxy resolution status.
-  void OnResolveProxyComplete(int result);
-
-  // |proxy_service_| specifies the proxy service that is to be used to find
-  // if access to |server_address_| goes through proxy server or not.
-  net::ProxyService* proxy_service_;
-
-  // |server_address_| specifies the server host and port pair for which we are
-  // trying to see if access to it, goes through proxy or not.
-  net::HostPortPair server_address_;
-
-  // |callback_| will be called after proxy resolution is completed.
-  OnResolvedCallback callback_;
-
-  // |proxy_info_| holds proxy information returned by ResolveProxy.
-  net::ProxyInfo proxy_info_;
-
-  // Indicate if there is a pending a proxy resolution. We use this to assert
-  // that there is no in-progress proxy resolution request.
-  bool has_pending_proxy_resolution_;
-  DISALLOW_COPY_AND_ASSIGN(ProxyDetector);
-};
-
-// This collects the network connectivity stats for UDP protocol for small
-// percentage of users who are participating in the experiment (by enabling
-// "UMA upload"). This method gets called only if UMA upload to the
-// server has succeeded.
-void CollectNetworkStats(const std::string& network_stats_server_url,
-                         IOThread* io_thread);
-
-// This starts a series of tests randomly selected among one of the three
-// choices of probe packet sizes: 100 Bytes, 500 Bytes, 1200 Bytes.
-void StartNetworkStatsTest(net::HostResolver* host_resolver,
-                           const net::HostPortPair& server_address,
-                           uint16 histogram_port,
-                           bool has_proxy_server);
-
-}  // namespace chrome_browser_net
-
-#endif  // CHROME_BROWSER_NET_NETWORK_STATS_H_