Keep track of network error in ProxyRetryInfo.

components/data_reduction_proxy/browser/data_reduction_proxy_usage_stats.h

 // Copyright 2014 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 COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_
 
 #include "base/callback.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/prefs/pref_member.h"
@@ skipping 46 matching lines @@
 
   // Given the |content_length| and associated |request|, records the
   // number of bypassed bytes for that |request| into UMAs based on bypass type.
   // |data_reduction_proxy_enabled| tells us the state of the
   // kDataReductionProxyEnabled preference.
   void RecordBypassedBytesHistograms(
       net::URLRequest& request,
       const BooleanPrefMember& data_reduction_proxy_enabled);
 
   void RecordBypassEventHistograms(const net::ProxyServer& bypassed_proxy,
-                                   int net_error,
-                                   bool did_fallback) const;
+                                   int net_error) const;
 
  private:
   enum BypassedBytesType {
     NOT_BYPASSED = 0,         /* Not bypassed. */
     SSL,                      /* Bypass due to SSL. */
     LOCAL_BYPASS_RULES,       /* Bypass due to client-side bypass rules. */
     AUDIO_VIDEO,              /* Audio/Video bypass. */
     TRIGGERING_REQUEST,       /* Triggering request bypass. */
     NETWORK_ERROR,            /* Network error. */
     BYPASSED_BYTES_TYPE_MAX   /* This must always be last.*/
@@ skipping 51 matching lines @@
 
   // Called when the unavailability status has changed. Runs on the UI thread.
   base::Callback<void(bool)> unavailable_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyUsageStats);
 };
 
 }  // namespace data_reduction_proxy
 
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_USAGE_STATS_H_