libchrome: Several upstreamable fixes from libchrome

base/metrics/sample_vector.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 "base/metrics/sample_vector.h"
 
 #include "base/logging.h"
 #include "base/metrics/bucket_ranges.h"
 
 namespace base {
 
 typedef HistogramBase::Count Count;
 typedef HistogramBase::Sample Sample;
 
 SampleVector::SampleVector(const BucketRanges* bucket_ranges)
     : SampleVector(0, bucket_ranges) {}
 
 SampleVector::SampleVector(uint64_t id, const BucketRanges* bucket_ranges)
     : HistogramSamples(id),
       local_counts_(bucket_ranges->bucket_count()),
       counts_(&local_counts_[0]),
       counts_size_(local_counts_.size()),
       bucket_ranges_(bucket_ranges) {
   CHECK_GE(bucket_ranges_->bucket_count(), 1u);
 }
 
 SampleVector::SampleVector(uint64_t id,
                            HistogramBase::AtomicCount* counts,
-                           size_t counts_size,
+                           size_t /*counts_size*/,
                            Metadata* meta,
                            const BucketRanges* bucket_ranges)
     : HistogramSamples(id, meta),
       counts_(counts),
       counts_size_(bucket_ranges->bucket_count()),
       bucket_ranges_(bucket_ranges) {
   CHECK_LE(bucket_ranges_->bucket_count(), counts_size_);
   CHECK_GE(bucket_ranges_->bucket_count(), 1u);
 }
 
@@ skipping 144 matching lines @@
     return;
 
   while (index_ < counts_size_) {
     if (subtle::NoBarrier_Load(&counts_[index_]) != 0)
       return;
     index_++;
   }
 }
 
 }  // namespace base