linux and chromeos: Turn on -Wunused-const-variable.

chrome/browser/metrics/perf_provider_chromeos.cc

 // Copyright (c) 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.
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 28 matching lines @@
 // before it is triggered. The following 2 variables determine the upper and
 // lower bound on the interval.
 // The reason we do not always want to collect the initial profile after a fixed
 // period is to not over-represent task X in the profile where task X always
 // runs at a fixed period after start-up. By selecting a period randomly between
 // a lower and upper bound, we will hopefully collect a more fair profile.
 const size_t kPerfCommandStartIntervalLowerBoundMinutes = 10;
 
 const size_t kPerfCommandStartIntervalUpperBoundMinutes = 20;
 
-const size_t kNumberOfSecondsInAMinute = 60;
-
 // Default time in seconds perf is run for.
 const size_t kPerfCommandDurationDefaultSeconds = 2;
 
 // Enumeration representing success and various failure modes for collecting and
 // sending perf data.
 enum GetPerfDataOutcome {
   SUCCESS,
   NOT_READY_TO_UPLOAD,
   NOT_READY_TO_COLLECT,
   INCOGNITO_ACTIVE,
@@ skipping 127 matching lines @@
 
   if (!perf_data_proto_.ParseFromArray(data.data(), data.size())) {
     AddToPerfHistogram(PROTOBUF_NOT_PARSED);
     perf_data_proto_.Clear();
     return;
   }
 
   state_ = READY_TO_UPLOAD;
 }
 } // namespace metrics