remove redundant DCHECK that a size_t variable >= 0

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"
 
 using std::vector;
@@ skipping 25 matching lines @@
 
 Count SampleVector::TotalCount() const {
   Count count = 0;
   for (size_t i = 0; i < counts_.size(); i++) {
     count += counts_[i];
   }
   return count;
 }
 
 Count SampleVector::GetCountAtIndex(size_t bucket_index) const {
-  DCHECK(bucket_index >= 0 && bucket_index < counts_.size());
+  DCHECK(bucket_index < counts_.size());
   return counts_[bucket_index];
 }
 
 scoped_ptr<SampleCountIterator> SampleVector::Iterator() const {
   return scoped_ptr<SampleCountIterator>(
       new SampleVectorIterator(&counts_, bucket_ranges_));
 }
 
 bool SampleVector::AddSubtractImpl(SampleCountIterator* iter,
                                    HistogramSamples::Operator op) {
@@ skipping 95 matching lines @@
     return;
 
   while (index_ < counts_->size()) {
     if ((*counts_)[index_] != 0)
       return;
     index_++;
   }
 }
 
 }  // namespace base