Fixes for re-enabling more MSVC level 4 warnings: components/ edition

components/domain_reliability/scheduler.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.
 
 #include "components/domain_reliability/scheduler.h"
 
 #include <algorithm>
 
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
 #include "components/domain_reliability/config.h"
 #include "components/domain_reliability/util.h"
 
 namespace {
 
-const unsigned kInvalidCollectorIndex = -1;
+const unsigned kInvalidCollectorIndex = static_cast<unsigned>(-1);
 
 const unsigned kDefaultMinimumUploadDelaySec = 60;
 const unsigned kDefaultMaximumUploadDelaySec = 300;
 const unsigned kDefaultUploadRetryIntervalSec = 60;
 
 const char* kMinimumUploadDelayFieldTrialName = "DomRel-MinimumUploadDelay";
 const char* kMaximumUploadDelayFieldTrialName = "DomRel-MaximumUploadDelay";
 const char* kUploadRetryIntervalFieldTrialName = "DomRel-UploadRetryInterval";
 
 unsigned GetUnsignedFieldTrialValueOrDefault(std::string field_trial_name,
@@ skipping 176 matching lines @@
     return base::TimeDelta::FromSeconds(0);
   else {
     // Don't back off more than 64x the original delay.
     if (failures > 7)
       failures = 7;
     return params_.upload_retry_interval * (1 << (failures - 1));
   }
 }
 
 }  // namespace domain_reliability