Record Lo-Fi NQE prediction accuracy at different intervals

components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
index 62e46d7f5e6052a265ce457d6de5deaaed030f82..46a93e0d25366e20f7dd859618cd357a7e74a565 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
@@ -9,11 +9,13 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "net/base/net_errors.h"
@@ -25,6 +27,11 @@
 
 class GURL;
 
+namespace base {
+class SingleThreadTaskRunner;
+class TickClock;
+}
+
 namespace net {
 class HostPortPair;
 class NetLog;
@@ -84,13 +91,13 @@ class DataReductionProxyConfig
  public:
   // The caller must ensure that all parameters remain alive for the lifetime
   // of the |DataReductionProxyConfig| instance, with the exception of
-  // |config_values| which is owned by |this|. |io_task_runner| is used to
-  // validate calls on the correct thread. |event_creator| is used for logging
-  // the start and end of a secure proxy check; |net_log| is used to create a
-  // net::BoundNetLog for correlating the start and end of the check.
+  // |config_values| which is owned by |this|. |event_creator| is used for
+  // logging the start and end of a secure proxy check; |net_log| is used to
+  // create a net::BoundNetLog for correlating the start and end of the check.
   // |config_values| contains the Data Reduction Proxy configuration values.
   // |configurator| is the target for a configuration update.
   DataReductionProxyConfig(
+      scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       net::NetLog* net_log,
       std::unique_ptr<DataReductionProxyConfigValues> config_values,
       DataReductionProxyConfigurator* configurator,
@@ -200,6 +207,13 @@ class DataReductionProxyConfig
   virtual void GetNetworkList(net::NetworkInterfaceList* interfaces,
                               int policy);
 
+  // Virtualized for testing. Returns the list of intervals at which accuracy of
+  // network quality prediction should be recorded.
+  virtual const std::vector<base::TimeDelta>&
+  lofi_accuracy_recording_intervals() const;
+
+  virtual base::TickClock* GetTickClock() const;
+
  private:
   friend class DataReductionProxyConfigTest;
   friend class MockDataReductionProxyConfig;
@@ -219,7 +233,9 @@ class DataReductionProxyConfig
   FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest, AutoLoFiParams);
   FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest,
                            AutoLoFiParamsSlowConnectionsFlag);
-  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest, AutoLoFiAccuracy);
+  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest, LoFiAccuracy);
+  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest,
+                           LoFiAccuracyNonZeroDelay);
 
   // Values of the estimated network quality at the beginning of the most
   // recent query of the Network Quality Estimator.
@@ -283,7 +299,8 @@ class DataReductionProxyConfig
 
   // Records Lo-Fi accuracy metric.

[Alexei Svitkine (slow), 2016/04/18 20:35:09]

Add a comment about measuring_duration. Per histograms.xml, only three values
are expected for it, right?  15/30/60

Actually, in that case, why pass it as a TimeDelta - maybe just an int?

[tbansal1, 2016/04/18 22:37:35]

Done.
Because this function compares delta between two time ticks with
|measuring_duration|. If I pass seconds, I would need to upgrade that back to
TimeDelta.

   void RecordAutoLoFiAccuracyRate(
-      const net::NetworkQualityEstimator* network_quality_estimator) const;
+      const net::NetworkQualityEstimator* network_quality_estimator,
+      const base::TimeDelta& measuring_duration) const;
 
   std::unique_ptr<SecureProxyChecker> secure_proxy_checker_;
 
@@ -296,6 +313,8 @@ class DataReductionProxyConfig
   // Contains the configuration data being used.
   std::unique_ptr<DataReductionProxyConfigValues> config_values_;
 
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
   // The caller must ensure that the |net_log_|, if set, outlives this instance.
   // It is used to create new instances of |bound_net_log_| on secure proxy
   // checks. |bound_net_log_| permits the correlation of the begin and end
@@ -357,6 +376,14 @@ class DataReductionProxyConfig
   // request headers are never modified in the control group.
   bool previous_state_lofi_on_;
 
+  // Intervals after the main frame request arrives at which accuracy of network
+  // quality prediction is recorded.
+  std::vector<base::TimeDelta> lofi_accuracy_recording_intervals_;
+
+  scoped_ptr<base::TickClock> tick_clock_;
+
+  base::WeakPtrFactory<DataReductionProxyConfig> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyConfig);
 };