Add missing (and remove superfluous) 'explicit' from constructors.

base/metrics/histogram_samples.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/histogram_samples.h"
 
 #include "base/compiler_specific.h"
 #include "base/pickle.h"
 
 namespace base {
 
 namespace {
 
 class SampleCountPickleIterator : public SampleCountIterator {
  public:
-  SampleCountPickleIterator(PickleIterator* iter);
+  explicit SampleCountPickleIterator(PickleIterator* iter);
 
   virtual bool Done() const OVERRIDE;
   virtual void Next() OVERRIDE;
   virtual void Get(HistogramBase::Sample* min,
                    HistogramBase::Sample* max,
                    HistogramBase::Count* count) const OVERRIDE;
  private:
   PickleIterator* const iter_;
 
   HistogramBase::Sample min_;
@@ skipping 90 matching lines @@
 }
 
 SampleCountIterator::~SampleCountIterator() {}
 
 bool SampleCountIterator::GetBucketIndex(size_t* index) const {
   DCHECK(!Done());
   return false;
 }
 
 }  // namespace base