Domain Reliability: Add sample_rate field to Beacon

components/domain_reliability/beacon.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_DOMAIN_RELIABILITY_BEACON_H_
 #define COMPONENTS_DOMAIN_RELIABILITY_BEACON_H_
 
 #include <string>
 
 #include "base/memory/scoped_vector.h"
@@ skipping 47 matching lines @@
   int http_response_code;
   // Elapsed time between starting and completing the request.
   base::TimeDelta elapsed;
   // Start time of the request.  Encoded as the request age in the final JSON.
   base::TimeTicks start_time;
   // Length of the chain of Domain Reliability uploads leading to this report.
   // Zero if the request was not caused by an upload, one if the request was
   // caused by an upload that itself contained no beacons caused by uploads,
   // et cetera.
   int upload_depth;
+  // "Weight" of this beacon -- the inverse of the sampling rate under which it
+  // was chosen to be reported.

[jkarlin, 2015/12/07 14:57:27]

Why inverse? Why not just report the sampling rate? 

[Deprecated (see juliatuttle), 2015/12/07 20:17:57]

Done.

+  int weight;

[jkarlin, 2015/12/07 14:57:27]

Why an int? You're losing significant data here.

[Deprecated (see juliatuttle), 2015/12/07 20:17:57]

In our own tests, we've only ever used things (other than 100%) like 5% or 10%.

[jkarlin, 2015/12/08 19:41:36]

But the sample_rate is a double in the range [0,1] right?

 
   // Okay to copy and assign.
 };
 
 }  // namespace domain_reliability
 
 #endif  // COMPONENTS_DOMAIN_RELIABILITY_BEACON_H_