Domain Reliability: Add sample_rate field to Beacon

components/domain_reliability/config.cc

 // 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.
 
 // Make sure stdint.h includes SIZE_MAX. (See C89, p259, footnote 221.)
 #ifndef __STDC_LIMIT_MACROS
 #define __STDC_LIMIT_MACROS 1
 #endif
 
 #include "components/domain_reliability/config.h"
@@ skipping 59 matching lines @@
   }
 
   for (const auto& url : collectors) {
     if (!url->is_valid())
       return false;
   }
 
   return true;
 }
 
-bool DomainReliabilityConfig::DecideIfShouldReportRequest(bool success) const {
+bool DomainReliabilityConfig::DecideIfShouldReportRequest(
+    bool success,
+    double* sample_rate_out) const {
   double sample_rate = success ? success_sample_rate : failure_sample_rate;
+  *sample_rate_out = sample_rate;
   return base::RandDouble() < sample_rate;
 }
 
 // static
 void DomainReliabilityConfig::RegisterJSONConverter(
     base::JSONValueConverter<DomainReliabilityConfig>* converter) {
   converter->RegisterCustomValueField<GURL>(
       "origin", &DomainReliabilityConfig::origin, &ConvertOrigin);
   converter->RegisterBoolField("include_subdomains",
                                &DomainReliabilityConfig::include_subdomains);
   converter->RegisterRepeatedCustomValue(
       "collectors", &DomainReliabilityConfig::collectors, &ConvertURL);
   converter->RegisterRepeatedString("path_prefixes",
                                     &DomainReliabilityConfig::path_prefixes);
   converter->RegisterDoubleField("success_sample_rate",
                                  &DomainReliabilityConfig::success_sample_rate);
   converter->RegisterDoubleField("failure_sample_rate",
                                  &DomainReliabilityConfig::failure_sample_rate);
 }
 
 }  // namespace domain_reliability